Name: synthesis of substrate-bound au nanowires via an active surface growth mechanism
Uploaded: 2018-07-18T15:00:00.000+00:00
Duration: 9 min 36 s
Description: Watch this Scientific Journal Video about Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism at JoVE.com

We gratefully acknowledge the financial support from National Natural Science Foundation of China (21703104), Jiangsu Science and Technology Plan (SBK2017041514) Nanjing Tech University (39837131), and SICAM Fellowship from Jiangsu National Synergetic Innovation Center for Advanced Materials.

Caution: Please check the material safety data sheets (MSDS) of the chemicals for detailed handling and storage instruction. Please be careful while handling the nanomaterials, as there may be unidentified risk. Please perform the experiments in a fume hood and wear appropriate personal protective equipment.
1. Synthesis of Seed Nanoparticles
Note: To avoid failure caused by the premature nucleation during the nanoparticle synthesis, wash the glassware and stir bar used in the synthesis with aqua regia and rinse thoroughly with water.
<ol>
	<li>Synthesis of 3-5 nm Au nanoparticles
	<ol>
		<li>Prepare a hydrogen tetrachloroaurate (III) (HAuCl4) solution by dissolving 10 mg of HAuCl4&#8729;3H2O in 1 mL of deionization&#160;water (DI water) in a 4 mL vial. Pipette 0.197 mL of the HAuCl4 solution into a 50 mL round-bottom flask.</li>
		<li>Add 19.7 mL of DI water to the flask to dilute the HAuCl4 solution.</li>
		<li>Dissolve 10 mg of sodium citrate in 1 mL of DI water in another 4 mL vial to prepare a 1% sodium citrate stock solution. Add 0.147 mL of the 1% sodium citrate solution to the diluted HAuCl4 solution prepared in step 1.1.2.</li>
		<li>Prepare a 0.1 M sodium borohydride (NaBH4) solution by dissolving 2.3 mg of NaBH4 in 0.6 mL of DI water.</li>
		<li>Quickly inject 0.6 mL of 0.1 M NaBH4 solution into the mixture from step 1.1.3 under vigorous stirring. Check for an immediate color change of the solution from pale yellow to bright orange.</li>
		<li>Stir the mixture for another 10 min. Wait for a gradual color change of the solution to reddish orange.</li>
		<li>Confirm the size of the obtained Au nanoparticles with UV-Vis spectroscopy and scanning electron microscopy (SEM).</li>
	</ol>
	</li>
	<li>Synthesis of 15 and 40 nm Au nanoparticles
	<ol>
		<li>Add 100 mL of DI water in a 250 mL round-bottom flask. Weigh 10 mg of HAuCl4&#8729;3H2O solid and dissolve it in the round-bottom flask.</li>
		<li>Add a magnetic stir bar into the flask and equip the flask with a condenser. Stir and heat the solution prepared in 1.2.1 to 100 &#176;C in an oil bath. Reflux the solution for 10 min.</li>
		<li>Weigh 40 mg of sodium citrate and dissolve it in 4 mL of DI water to prepare a 1% sodium citrate stock solution.</li>
		<li>To synthesize 15 nm Au nanoparticles, add 3 mL of the 1% sodium citrate solution from step 1.2.3 to the boiled mixture with a syringe. 
		Note: The color of the solution turns gray in 1 min, and then gradually to red.
		<ol>
			<li>To synthesize 40 nm Au nanoparticles, inject 1.5 mL of the 1% sodium citrate solution to the boiling solution from step 1.2.2 with a syringe. Keep the solution boiling until it changes to red in about 10 min. 
			Note: The color of the solution changes from transparent to dark gray, then to black, and finally to purple in about 1 min.</li>
		</ol>
		</li>
		<li>Continue to reflux the reaction solution for 30 min. Cool down the solution to room temperature at ambient conditions.</li>
		<li>Characterize the size and uniformity of the resulting Au nanoparticles with UV-Vis spectroscopy and SEM.</li>
	</ol>
	</li>
</ol>
2. Synthesis of Au Nanowires (Length = ~500 nm ) on Silicon (Si) Wafers and Various Substrates
<ol>
	<li>Prepare the substrate for seed adsorption.
	<ol>
		<li>Cut the Si wafer into 5 mm &#180; 5 mm pieces. Clean the Si wafer pieces with DI water and ethanol sequentially in an ultrasonic bath, each for 15 min.</li>
		<li>Treat the Si wafer with 29.6 W of O2 plasma (operated at 220 V) for 20 min. 
		Note: The surface of the wafer becomes hydrophilic.</li>
		<li>Prepare a 5 mM 3-aminopropyltriethoxysilane (APTES) solution by dissolving 11.1 mg of APTES to a mixture of DI water (5 mL) and ethanol (5 mL) in a 20 mL vial.</li>
		<li>Soak a piece of Si wafer in the APTES solution prepared in step 2.1.3 in a 20 mL vial for 30 min.</li>
		<li>Take out the Si wafer and wash it thoroughly with ethanol and DI water.</li>
	</ol>
	</li>
	<li>Adsorb seed nanoparticles onto the substrate.
	<ol>
		<li>Soak the Si wafer in the 3-5 nm Au seeds solution prepared in step 1.1 for 2 h.
		<ol>
			<li>To grow Au nanowires from 15 nm Au seeds, soak the Si wafer in the 15 nm Au nanoparticle solution for 2 h.</li>
			<li>To grow Au nanowires from 40 nm Au seeds, soak the Si wafer in the 40 nm Au nanoparticle solution for 2 h.</li>
		</ol>
		</li>
		<li>Take out the Si wafer and wash it with 50 mL of DI water to remove unabsorbed Au nanoparticles.</li>
	</ol>
	</li>
	<li>Grow the substrate-bound Au nanowires.
	<ol>
		<li>Prepare a 1.65 mM 4-mercaptobenzoic acid (4-MBA) solution by dissolving 2.5 mg of 4-MBA in 10 mL of ethanol.</li>
		<li>Prepare a 5.10 mM HAuCl4 solution by dissolving 20.1 mg of HAuCl4&#8729;3H2O in a mixture of 5 mL of ethanol and 5 mL of DI water.</li>
		<li>Prepare a 12.3 mM L-ascorbic acid solution by dissolving 21.7 mg of L-ascorbic acid in 10 mL of DI water.</li>
		<li>Mix 0.5 mL of 5.10 mM HAuCl4 solution with 0.5 mL of 1.65 mM 4-MBA solution in a 10 mL vial.</li>
		<li>Soak the seed-adsorbed Si wafer from step 2.2.2 in the mixed solution prepared in step 2.3.4.</li>
		<li>Add 0.5 mL of 12.3 mM L-ascorbic acid solution into the wafer-soaked mixed solution. Shake the vial gently to evenly mix the solution.</li>
		<li>Leave the wafer and the solution undisturbed for 15 min. Check the bubble formation during the growth process, and the color change of the surface of the Si wafer from shiny gray to reddish brown.</li>
		<li>Take out the Si wafer and rinse it with ethanol and DI water. Dry the Si wafer at ambient conditions and wait for the surface of the wafer to turn to gold.</li>
		<li>Characterize the morphology of the Au nanowires with the SEM.</li>
	</ol>
	</li>
	<li>For growth of Au nanowires on a glass slide, Al2O3, SrTiO3, LaAlO3, indium tin oxide (ITO) and F-doped tin oxide (FTO) substrates, follow the same procedures, including the cleaning processes.</li>
</ol>
3. Synthesis of Au Nanowires with Different Ligands
<ol>
	<li>Synthesis of Au nanowire forests with various thiolated ligands: 2-naphthalenethiol (2-NpSH), 4-mercaptophenylacetic acid (4-MPAA) and 3-mercaptobenzoic acid (3-MBA).
	<ol>
		<li>Treat the Si wafer following the same procedures in steps 2.1-2.2.</li>
		<li>Prepare a 1.65 mM 2-NpSH solution by dissolving 2.6 mg of 2-NpSH in 10 mL of ethanol.
		<ol>
			<li>Prepare a 1.65 mM 4-MPAA solution by dissolving 2.8 mg of 4-MPAA in 10 mL of ethanol.</li>
			<li>Prepare a 1.65 mM 3-MBA solution by dissolving 2.5 mg of 3-MBA in 10 mL of ethanol.</li>
		</ol>
		</li>
		<li>Prepare the 5.10 mM HAuCl4 solution and 12.3 mM L-ascorbic acid solution following the same procedure in steps 2.3.1-2.3.3.</li>
		<li>In a 10 mL vial, mix 0.5 mL of the HAuCl4 solution with 0.5 mL of 2-NpSH solution, and shake the mixture to get a homogeneous solution.
		<ol>
			<li>In a 10 mL vial, mix 0.5 mL of the HAuCl4 solution with 0.5 mL of 4-MPAA solution, and shake the mixture to get a homogeneous solution.</li>
			<li>In a 10 mL vial, mix 0.5 mL of the HAuCl4 solution with 0.5 mL of 3-MBA solution, and shake the mixture to get a homogeneous solution.</li>
		</ol>
		</li>
		<li>Add 0.5 mL of 12.3 mM L-ascorbic acid solution to the wafer-soaked mixed solution. Shake the vial gently to get an evenly mixed solution.</li>
		<li>Leave the wafer and the solution undisturbed for 15 min. Observe the surface of the Si wafer turning slowly from shiny gray to reddish brown.</li>
		<li>Take out the Si wafer and rinse it with ethanol and DI water, and dry the Si wafer at ambient conditions until the surface of the wafer turns to gold.</li>
		<li>Confirm the Au nanowires forest structure with SEM.</li>
	</ol>
	</li>
	<li>Synthesis of tapered Au nanowires with mixed ligands.
	<ol>
		<li>Synthesis of thickened Au nanowires with mixed ligands of 4-MBA and 3-mercaptopropanoic acid (3-MPA) (c4-MBA/c3-MPA = 3:1).
		<ol>
			<li>Treat the Si wafer following the same procedures in steps 2.1-2.2, except dilute the seed solution 100 times.</li>
			<li>Prepare a 3 mM 4-MBA solution by dissolving 4.6 mg of 4-MBA in 10 mL of ethanol.</li>
			<li>Prepare a 3 mM 3-MPA solution by dissolving 3.2 mg of 3-MPA in 10 mL of ethanol.</li>
			<li>Mix 0.75 mL of 3 mM 4-MBA solution with 0.25 mL of 3 mM 3-MPA solution (in a 10 mL vial. Shake gently to get a homogeneous solution.</li>
			<li>Prepare the 5.10 mM HAuCl4 solution and 12.3 mM L-ascorbic acid solution following the same procedure in steps 2.3.2-2.3.3.</li>
			<li>Add 0.5 mL of 5.10 mM HAuCl4 solution to the mixed solution in step 3.2.1.4 and shake gently to homogenize the solution.</li>
			<li>Soak the Si wafer from step 3.2.1.1 in the mixed solution in a 10 mL vial. Add 0.5 mL of 12.3 mM L-ascorbic acid solution to the mixed solution.</li>
			<li>After 10 min, take the Si wafer out and rinse with ethanol and DI water.</li>
			<li>Dry the wafer at ambient conditions and confirm the structure by SEM.</li>
		</ol>
		</li>
		<li>Synthesize tapered Au nanowires with mixed ligand of 4-MBA and 3-MPA (c4-MBA/c3-MPA = 6:4). Follow the same procedures in step 3.2.1 with 0.6 mL of 3 mM 4-MBA solution and 0.4 mL of 3 mM 3-MPA solution instead.</li>
		<li>Synthesize tapered Au nanowires with mixed ligands of 4-MBA and 3-MPA (c4-MBA/c3-MPA = 1:1). Follow the same procedures in step 3.2.1 with 0.5 mL of 3 mM 4-MBA solution and 0.5 mL of 3 mM 3-MPA solution instead.</li>
	</ol>
	</li>
</ol>
4. Synthesis of Au Nanowire-Based Complex Nanostructures
<ol>
	<li>Synthesis of segmental Au nanowires with thick-thin-thick-thin segments.
	<ol>
		<li>Treat the Si wafer following the same procedures in steps 2.1-2.2.</li>
		<li>Prepare a 1.65 mM 4-MBA solution by dissolving 2.5 mg of 4-MBA in 10 mL of ethanol.</li>
		<li>Prepare a 0.0830 mM 4-MBA solution by diluting the 1.65 mM 4-MBA solution 20 times.</li>
		<li>Prepare the HAuCl4 and L-ascorbic acid solution following the same procedures in steps 2.3.2-2.3.3.</li>
		<li>Prepare 1.5 mL of growth solution A by mixing 0.5 mL of 1.65 mM 4-MBA solution, 0.5 mL of 5.10 mM HAuCl4 solution, and 0.5 mL of 12.3 mM L-ascorbic acid solution (the final concentration: c4-MBA = 0.550 mM, cHAuCl4 = 1.70 mM, cL-ascorbic acid = 4.10 mM).</li>
		<li>Prepare 1.5 mL of growth solution B by mixing 0.5 mL of 0.0830 mM 4-MBA solution, 0.5 mL of 5.10 mM HAuCl4 solution, 0.5 mL of 12.3 mM L-ascorbic acid solution&#160;(the final concentration: c4-MBA = 0.0280 mM, cHAuCl4 = 1.70 mM, cL-ascorbic acid = 4.10 mM).</li>
		<li>Immerse the Si wafer in a 10 mL vial containing growth solution B for about 1 min.</li>
		<li>Rapidly transfer the Si wafer without drying to another 10 mL vial containing growth solution A and leave it to grow for 2 min.</li>
		<li>Repeat steps 4.1.7-4.1.8 one more time.</li>
		<li>Take the Si wafer out and rinse with 50 mL of ethanol and 50 mL of DI water.</li>
		<li>Confirm the structure of the resulting segmented Au nanowires by SEM.</li>
	</ol>
	</li>
	<li>Synthesis of the nanoflowers
	<ol>
		<li>Treat the Si wafer following the same procedures in steps 2.1-2.2, except with a 5 min O2 plasma treatment.</li>
		<li>Soak the Si wafer in a 10 mL vial containing a 10000x diluted 3-5 nm Au seeds solution for 15 min.</li>
		<li>Wash the Si wafer from step 4.2.2 thoroughly with DI water to remove unabsorbed Au nanoparticles.</li>
		<li>Prepare a growth solution containing 0.550 mM 4-MBA, 1.70 mM HAuCl4, and 4.10 mM L-ascorbic-acid, following the same procedures in step 4.1.5.</li>
		<li>Soak the wafer in a 10 mL vial containing the growth solution for 30 s.</li>
		<li>Remove the wafer from the growth solution and leave a thin layer of the solution (~ 13- 15 &#956;L) on the wafer.</li>
		<li>Quickly blow-dry the wafer at room temperature.</li>
		<li>Confirm the nanoflower structure by SEM.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Yao, S. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Compartment-less+Nonenzymatic+Glucose-air+Fuel+Cell+with+Nitrogen-doped+Mesoporous+Carbons+and+Au+Nanowires+as+Catalysts.">A Compartment-less Nonenzymatic Glucose-air Fuel Cell with Nitrogen-doped Mesoporous Carbons and Au Nanowires as Catalysts.</a> Energy &amp; Environmental Science. 6, 3600-3604 (2013).</li><li>Gu, H. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Efficient+Synthesis+of+N-Substituted+Isoindolinones+and+Phthalazinones+Using+Pt+Nanowires+as+Catalysts.">Highly Efficient Synthesis of N-Substituted Isoindolinones and Phthalazinones Using Pt Nanowires as Catalysts.</a> Organic Letters. 14, 1876-1879 (2012).</li><li>Patolsky, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanowire-based+Nanoelectronic+Devices+in+the+Life+sciences.">Nanowire-based Nanoelectronic Devices in the Life sciences.</a> MRS Bulletin. 32, 142-149 (2007).</li><li>Schwarzacher, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Templated+Electrodeposition+of+Silver+Nanowires+in+a+Nanoporous+Polycarbonate+Membrane+from+a+Nonaqueous+Ionic+Liquid+Electrolyte.">Templated Electrodeposition of Silver Nanowires in a Nanoporous Polycarbonate Membrane from a Nonaqueous Ionic Liquid Electrolyte.</a> Applied Physics A-Mater. 86, 373-375 (2007).</li><li>Song, L. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Template-Electrodeposition+Preparation+and+Structural+Properties+of+CdS+Nanowire+Arrays.">Template-Electrodeposition Preparation and Structural Properties of CdS Nanowire Arrays.</a> Microelectronic Engineering. 83, 1971-1974 (2006).</li><li>Song, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+New+Twist+on+Nanowire+Formation:+Screw-Dislocation-Driven+Growth+of+Nanowires+and+Nanotubes.">A New Twist on Nanowire Formation: Screw-Dislocation-Driven Growth of Nanowires and Nanotubes.</a> Journal of Physical Chemistry Letters. 1, 1472-1480 (2010).</li><li>Lim, S. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlled+Modulation+of+Diameter+and+Composition+along+Individual+III-V+Nitride+Nanowires.">Controlled Modulation of Diameter and Composition along Individual III-V Nitride Nanowires.</a> Nano Letters. 13, 331-336 (2012).</li><li>Xu, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+Fabrication+of+CdS+Nanowire+Arrays+in+Porous+Anodic+Aluminum+Oxide+Templates.">Electrochemical Fabrication of CdS Nanowire Arrays in Porous Anodic Aluminum Oxide Templates.</a> Journal of Physical Chemistry. 33, 14037-14047 (1996).</li><li>Lee, S. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-density,+Ordered+Ultraviolet+Light-emitting+ZnO+Nanowire+Arrays.">High-density, Ordered Ultraviolet Light-emitting ZnO Nanowire Arrays.</a> Advanced Materials. 15, 838-841 (2003).</li><li>Tang, Y. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemically+Induced+Sol-Gel+Preparation+of+Single-Crystalline+TiO2+Nanowires.">Electrochemically Induced Sol-Gel Preparation of Single-Crystalline TiO2 Nanowires.</a> Nano Letters. 2, 717-720 (2002).</li><li>Yang, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vapor-liquid-solid+Growth+of+Silicon+Nanowires+Using+Organosilane+as+Precursor.">Vapor-liquid-solid Growth of Silicon Nanowires Using Organosilane as Precursor.</a> Chemical Communications. 46, 6105-6107 (2010).</li><li>Xia, Y. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrathin+Gold+Nanowires+Can+Be+Obtained+by+Reducing+Polymeric+Strands+of+Oleylamine&#8722;AuCl+Complexes+Formed+via+Aurophilic+Interaction.">Ultrathin Gold Nanowires Can Be Obtained by Reducing Polymeric Strands of Oleylamine&#8722;AuCl Complexes Formed via Aurophilic Interaction.</a> Journal of the American Chemical Society. 130, 8900-8901 (2008).</li><li>Miguel, J. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helical+Growth+of+Ultrathin+Gold-Copper+Nanowires.">Helical Growth of Ultrathin Gold-Copper Nanowires.</a> Nano Letters. 16, 1568-1573 (2016).</li><li>Sun, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrathin+Au+Nanowires+and+Their+Transport+Properties.">Ultrathin Au Nanowires and Their Transport Properties.</a> Journal of the American Chemical Society. 130, 8902-8903 (2008).</li><li>Sun, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+Au+Nanowires+at+the+Interface+of+Air/Water.">Growth of Au Nanowires at the Interface of Air/Water.</a> Journal of Physical Chemistry. C. 113, 15196-15200 (2009).</li><li>Wu, H. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructured+Gold+Architectures+Formed+through+High+Pressure-Driven+Sintering+of+Spherical+Nanoparticle+Arrays.">Nanostructured Gold Architectures Formed through High Pressure-Driven Sintering of Spherical Nanoparticle Arrays.</a> Journal of the American Chemical Society. 132, 12826-12828 (2010).</li><li>Wu, H. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure-Driven+Assembly+of+Spherical+Nanoparticles+and+Formation+of+1D-Nanostructure+Arrays.">Pressure-Driven Assembly of Spherical Nanoparticles and Formation of 1D-Nanostructure Arrays.</a> Angewandte Chemie International Edition. 7, 8431-8434 (2010).</li><li>Li, B. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress-induced+Phase+Transformation+and+Optical+Coupling+of+Silver+Nanoparticle+Superlattices+into+Mechanically+Stable+Nanowires.">Stress-induced Phase Transformation and Optical Coupling of Silver Nanoparticle Superlattices into Mechanically Stable Nanowires.</a> Nature Communications. 5, 4179 (2014).</li><li>Chen, H. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Forest+of+Gold+Nanowires:+A+New+Type+of+Nanocrystal+Growth.">Forest of Gold Nanowires: A New Type of Nanocrystal Growth.</a> ACS Nano. 7, 2733-2740 (2013).</li><li>Wang, Y. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploiting+Rayleigh+Instability+in+Creating+Parallel+Au+Nanowires+with+Exotic+Arrangements.">Exploiting Rayleigh Instability in Creating Parallel Au Nanowires with Exotic Arrangements.</a> Small. 12, 930-938 (2016).</li><li>Wang, Y. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Thiolated+Ligands+in+Au+Nanowires+Synthesis.">Effect of Thiolated Ligands in Au Nanowires Synthesis.</a> Small. 13, 1702121 (2017).</li><li>Gedanken, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+surface+chemistry+of+Au+colloids+and+their+interactions+with+functional+amino+acids.">The surface chemistry of Au colloids and their interactions with functional amino acids.</a> Journal of Physical Chemistry B. 108, 4046-4052 (2004).</li><li>Xia, Y. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shape-Controlled+Synthesis+of+Pd+Nanocrystals+in+Aqueous+Solutions.">Shape-Controlled Synthesis of Pd Nanocrystals in Aqueous Solutions.</a> Advanced Functional Materials. 19, 189-200 (2009).</li></ol>

The authors have nothing to disclose.

The mechanism of this active surface growth governed nanowire synthesis has been discussed comprehensively in previous work19. In addition, the effects of seed sizes and types as well as the effect of ligand types and sizes have also been investigated20,21. Generally. the nanowire growth is very different from previous reported routes. No template is required, and the asymmetric growth is induced by the differences between the ligand-cappe...

Typical of one dimensional nanomaterials, nanowires possess both the bulk-related properties and the unique properties originated from the quantum effects of the nanoscale structure. As a bridge between the nanoscale and the bulk scale materials, they have been widely applied in various fields of catalysis, sensing, and nanoelectronic devices, etc.1,2,3.
However, the synthesis of nanowires has long been a great challenge, as it usually requires breaking the intrinsic symmetry in the crystals. Traditionally, a template is employed to regulate the deposition of materials. For instance, template-electrodeposition has been used for the formation of various types of nanowires like Ag nanowires and CdS nanowires4,5,6,7,8,9,10. Another common approach is vapor-liquid-solid (VLS) growth, which employs a molten catalyst to induce the anisotropic growth on the substrate at an elevated temperature11. Common strategies for the synthesis of metal nanowires are the polyol methods for Ag nanowires and the oleylamine-assisted ultrathin Au nanowires12,13,14,15. Both approaches are material-specific, and the nanowire parameters are not readily tuned during the synthesis. In addition, metal nanowires can also be formed by the pressure-driven method, where the assembled metal nanoparticles are mechanically compressed and fused into nanowires16,17,18.
Recently, we reported a distinctive method to synthesis Au nanowires19. With the assist of a thiolated small molecule ligand, the nanowires could grow and form a vertically aligned array on the bulk Si wafer substrate at ambient conditions. It was found that the ligands play an important role in the symmetry-breaking growth. It binds to the surface of the substrate-adsorbed Au seeds strongly, forcing the Au to deposit selectively at the ligand-deficient interface between seeds and substrate. The interface between the newly deposited Au and the substrate remains ligand deficient, therefore, the active surface exists throughout the whole growth. By tuning the ligand concentration, the seed type and concentration as well as several other parameters, a series of Au nanowire-based nanostructures could be synthesized.
In this work, we will provide a detailed protocol for this convenient Au nanowires synthesis. The derived synthesis is also presented, including the synthesis of Au nanowires with hydrophobic surface property, Au nanowires on other substrates, tapered Au nanowires by mixing two ligands and the nanowire-based Au nanostructures formed by tuning the growth conditions.

<table><tbody><tr><td>Trisodium citrate dihydrate</td><td>Alfa Aesar</td><td>LoT: 5008F14U</td><td></td></tr><tr><td>Sodium borohydride</td><td>Fluka</td><td>LoT: STBG0330V</td><td>NaBH4</td></tr><tr><td>Hydrogen tetrachloroaurate(III) trihydrate</td><td>Alfa Aesar</td><td>LoT: T19C006</td><td>HAuCl4</td></tr><tr><td>3-aminopropyltriethoxysilane</td><td>J&amp;amp;K Scientific</td><td>LoT: LT20Q102</td><td>APTES</td></tr><tr><td>L-ascorbic acid&amp;nbsp;</td><td>Sigma-Aldrich</td><td>LoT: SLBL9227V</td><td></td></tr><tr><td>4-mercaptobenzoic acid</td><td>Sigma-Aldrich</td><td>LoT: MKBV5048V</td><td>4-MBA</td></tr><tr><td>2-Naphthalenethiol</td><td>Sigma-Aldrich</td><td>LoT: BCBP4238V</td><td>2-NpSH</td></tr><tr><td>4-Mercaptophenylacetic acid</td><td>Alfa Aesar</td><td>LoT: 10199160</td><td>4-MPAA</td></tr><tr><td>3-mercaptobenzoic acid</td><td>Aladdin</td><td>LoT: G1213027</td><td>3-MBA</td></tr><tr><td>3-Mercaptopropionic acid</td><td>Aladdin</td><td>LoT: E1618095</td><td>3-MPA</td></tr><tr><td>absolute ethanol</td><td>Sinopharm chemical Reagent</td><td>20170802</td><td></td></tr><tr><td>Silicon wafer</td><td>Zhe Jiang lijing</td><td>P</td><td>Si</td></tr><tr><td>Scanning Electron Microscope</td><td>Quanta FEG 250</td><td></td><td>SEM</td></tr><tr><td>Centrifuge&amp;nbsp;</td><td>Eppendorf</td><td>5424</td><td></td></tr><tr><td>Ultrasonic cleaner&amp;nbsp;</td><td>Kun Shan hechuang</td><td></td><td></td></tr><tr><td>Ultra-pure water system</td><td>NanJing qianyan</td><td>UP6682-10-11</td><td>for deionized water</td></tr><tr><td>Plasma cleaner</td><td>Harrick Plasma</td><td>PDC-002</td><td>for oxygen plasma</td></tr></tbody></table>

synthesis of substrate-bound au nanowires via an active surface growth mechanism

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a challenge, as it requires asymmetric growth of symmetric crystals. Here, we report a distinctive synthesis of substrate-bound Au nanowires. This template-free synthesis employs thiolated ligands and substrate adsorption to achieve the continuous asymmetric deposition of Au in solution at ambient conditions. The thiolated ligand prevented the Au deposition on the exposed surface of the seeds, so the Au deposition only occurs at the interface between the Au seeds and the substrate. The side of the newly deposited Au nanowires is immediately covered with the thiolated ligand, while the bottom facing the substrate remains ligand-free and active for the next round of Au deposition. We further demonstrate that this Au nanowire growth can be induced on various substrates, and different thiolated ligands can be used to regulate the surface chemistry of the nanowires. The diameter of the nanowires can also be controlled with mixed ligands, in which another &#34;bad&#34; ligand could turn on the lateral growth. With the understanding of the mechanism, Au nanowire-based nanostructures can be designed and synthesized.

The Au nanoparticle seeds, substrate-bound Au nanowires and Au nanowire-based derivative nanostructures are characterized with SEM. Figure 1 shows the representative SEM images of the 3-5 nm Au nanoparticles, 15 nm Au Nanoparticles and 40 nm Au nanoparticles adsorbed on the Si wafer, confirming their sizes, adsorption and distribution. The Au nanowires grown from the respective seeds on the Si wafer substrate are also presented. The representative SEM images ...

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Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

We report a solution-based method to synthesize substrate-bound Au nanowires. By tuning the molecular ligands used during the synthesis, the Au nanowires can be grown from various substrates with different surface properties. Au nanowire-based nanostructures can also be synthesized by adjusting the reaction parameters.

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

synthesis-substrate-bound-au-nanowires-via-an-active-surface-growth

Research

JoVE Journal

Chemistry

7.7K Views.  Nanjing Tech University. Wij rapporteren een oplossingsgerichte methode voor het synthetiseren van substraat-gebonden Au nanowires. Door de moleculaire liganden gebruikt tijdens de synthese tuning, kunnen de Au nanowires worden gekweekt uit verschillende ondergronden met verschillende oppervlakte-eigenschappen. Au nanowire gebaseerde nanostructuren kan ook gesynthetiseerd worden door het aanpassen van de parameters van de reactie.

Video: Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and scalable technique efficiently functionalizes metallic nanoparticles with thiol-ligands in a miscible water/organic solvent mixture allowing for rapid grafting of thiol groups onto the gold nanoparticle surface. The hydrophobic ligands on the nanoparticles then quickly phase separate the nanoparticles from the aqueous based suspension and confine them to the air-fluid interface. This drives the ligand-capped nanoparticles to form monolayer domains at the air-fluid interface.&#160; The use of water-miscible organic solvents is important as it enables the transport of the nanoparticles from the interface onto template-free substrates.&#160; The flow is mediated by a surface tension gradient3,4 and creates macroscopic, high-density, monolayer nanoparticle-ligand films.&#160; This self-assembly technique may be generalized to include the use of particles of different compositions, size, and shape and may lead to an efficient assembly method to produce low-cost, macroscopic, high-density, monolayer nanoparticle films for wide-spread applications.

A simple, robust and scalable technique to functionalize and self-assemble macroscopic nanoparticle-ligand monolayer films onto template-free substrates is described in this protocol.

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and ...

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

Engineering

Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest in using nano-colloids for photo-thermal ablation, drug delivery and many other biomedical applications 6. Gold is particularly used because of its low toxicity 7-9. A property of metal nano-colloids is that they can have a strong surface plasmon resonance 10. The peak of the surface plasmon resonance mode depends on the structure and composition of the metal nano-colloids. Since the surface plasmon resonance mode is stimulated with light there is a need to have the peak absorbance in the near infrared where biological tissue transmissivity is maximal 11, 12.
We present a method to synthesize star shaped colloidal gold, also known as star shaped nanoparticles 13-15 or nanostars 16. This method is based on a solution containing silver seeds that are used as the nucleating agent for anisotropic growth of gold colloids 17-22. Scanning electron microscopy (SEM) analysis of the resulting gold colloid showed that 70 % of the nanostructures were nanostars. The other 30 % of the particles were amorphous clusters of decahedra and rhomboids. The absorbance peak of the nanostars was detected to be in the near infrared (840 nm). Thus, our method produces gold nanostars suitable for biomedical applications, particularly for photo-thermal ablation.

We synthesized star shaped gold nanostars using a silver seed mediated growth method. The diameter of the nanostars ranges from 200 to 300 nm and the number of tips vary from 7 to 10. The nanoparticles have a broad surface plasmon resonance mode centered in the near infrared.

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest ...

Bioengineering

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Large Area Substrate-Based Nanofabrication of Controllable and Customizable Gold Nanoparticles Via Capped Dewetting

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and high-density data storage have demonstrated the potential benefit of their use in industrial applications. These applications require precise control over nanoparticle size, spacing, and sometimes shape. These requirements have resulted in the use of time and cost intensive processing steps to produce nanoparticles, thus making the transition to industrial application unrealistic. This protocol will resolve this issue by providing a scalable and affordable method for the large-area production of nanoparticle films with improved nanoparticle control compared to the current techniques. In this article, the process will be demonstrated with gold, but other metals can also be used.

This protocol details a novel nano-manufacturing technique that can be used to make controllable and customizable nanoparticle films over large areas based on the self-assembly of dewetting of capped metal films.

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and ...

Growth of Gold Dendritic Nanoforests on Titanium Nitride-coated Silicon Substrates

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a fluoride-assisted galvanic replacement reaction (FAGRR) is employed for the rapid and easy deposition of gold dendritic nanoforests (Au DNFs) on the TiN/Si substrates. Scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy patterns of TiN/Si and Au DNFs/TiN/Si samples validate that the synthesis process is accurately controlled. Under the reaction conditions in this study, the thickness of the Au DNFs increases linearly to 5.10 &#177; 0.20 &#181;m within 15 min of the reaction. Therefore, the employed synthesis procedure is a simple and rapid approach for preparing Au DNFs/TiN/Si composites.

This study presents a feasible procedure for synthesizing gold dendritic nanoforests on titanium nitride/silicon substrates. The thickness of gold dendritic nanoforests increases linearly within 15 min of a synthesis reaction.

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of ...

Studying the Effects of Temperature on the Nucleation and Growth of Nanoparticles by Liquid-Cell Transmission Electron Microscopy

Temperature control is a recent development that provides an additional degree of freedom to study nanochemistry by liquid cell transmission electron microscopy. In this paper, we describe how to prepare an in situ heating experiment for studying the effect of temperature on the formation of gold nanoparticles driven by radiolysis in water. The protocol of the experiment is fairly simple involving a special liquid cell with uniform heating capabilities up to 100 &#176;C, a liquid-cell TEM holder with flow capabilities and an integrated interface for controlling the temperature. We show that the nucleation and growth mechanisms of gold nanoparticles are drastically impacted by the temperature in liquid cell. Using STEM imaging and nanodiffraction, the evolution of the density, size, shape and atomic structure of the growing nanoparticles are revealed in real time. Automated image processing algorithms are exploited to extract useful quantitative data from video sequences, such as the nucleation and growth rates of nanoparticles. This approach provides new inputs for understanding the complex physico-chemical processes at play during the liquid-phase synthesis of nanomaterials.

Temperature control during liquid-phase electron microscopy experiments opens up new perspectives of studying the dynamic of nanoparticles in liquid environments mimicking their formation or application media. Using recently developed heating liquid cells, we directly observed the influence of temperature on the nucleation and growth processes of gold nanoparticles in water.

Temperature control is a recent development that provides an additional degree of freedom to study nanochemistry by liquid cell transmission electron ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

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