The authors have no acknowledgements.

1. Precursor Solution Preparation
NOTE: Please consult all relevant material safety data sheets (MSDS) before use. Several of the chemicals used in this procedure are harmful and/or toxic to humans. Nanomaterials may have additional hazards compared to their bulk counterpart. Please use the appropriate safety measures and personal protective equipment.
<ol>
	<li>Place 5 g of titanium(IV) n-butoxide, 1 g of polyvinylpyrrolidone (PVP), 1 mL of glacial acetic acid, and 10 mL of absolute ethanol...

<ol>
	<li>O'Regan, B., Gr&#228;tzel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+low-cost,+high-efficiency+solar+cell+based+on+dye-sensitized+colloidal+TiO2+films.">A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films.</a> Nature. 353 (6346), 737-740 (1991).</li><li>Lee, C. H., Chiu, W. H., Lee, K. M., Hsieh, W. F., Wu, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+performance+of+flexible+dye-sensitized+solar+cells+by+introducing+an+interfacial+layer+on+Ti+substrates.">Improved performance of flexible dye-sensitized solar cells by introducing an interfacial layer on Ti substrates.</a> J Mat Chem. 21 (13), 5114-5119 (2011).</li><li>Burschka, J., Pellet, 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=Sequential+deposition+as+a+route+to+high-performance+perovskite-sensitized+solar+cells.">Sequential deposition as a route to high-performance perovskite-sensitized solar cells.</a> Nature. 499 (7458), 316-319 (2013).</li><li>Ohsaki, Y., Masaki, 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=Dye-sensitized+TiO2+nanotube+solar+cells:+fabrication+and+electronic+characterization.">Dye-sensitized TiO2 nanotube solar cells: fabrication and electronic characterization.</a> Phys Chem Chem Phys. 7 (24), 4157-4163 (2005).</li><li>Mor, G. K., Shankar, K., Paulose, M., Varghese, O. K., Grimes, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+Photocleavage+of+Water+Using+Titania+Nanotube+Arrays.">Enhanced Photocleavage of Water Using Titania Nanotube Arrays.</a> Nano Letters. 5 (1), 191-195 (2005).</li><li>Feng, X., Shankar, K., Varghese, O. K., Paulose, M., Latempa, T. J., Grimes, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vertically+Aligned+Single+Crystal+TiO2+Nanowire+Arrays+Grown+Directly+on+Transparent+Conducting+Oxide+Coated+Glass:+Synthesis+Details+and+Applications.">Vertically Aligned Single Crystal TiO2 Nanowire Arrays Grown Directly on Transparent Conducting Oxide Coated Glass: Synthesis Details and Applications.</a> Nano Letters. 8 (11), 3781-3786 (2008).</li><li>Roy, P., Berger, S., Schmuki, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TiO2+Nanotubes:+Synthesis+and+Applications.">TiO2 Nanotubes: Synthesis and Applications.</a> Angewandte Chemie International Edition. 50 (13), 2904-2939 (2011).</li><li>Macdonald, T. J., Xu, 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=NiO+Nanofibers+as+a+Candidate+for+a+Nanophotocathode.">NiO Nanofibers as a Candidate for a Nanophotocathode.</a> Nanomaterials. 4 (2), 256-266 (2014).</li><li>Chuangchote, S., Sagawa, T., Yoshikawa, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+dye-sensitized+solar+cells+using+electrospun+TiO2+nanofibers+as+a+light+harvesting+layer.">Efficient dye-sensitized solar cells using electrospun TiO2 nanofibers as a light harvesting layer.</a> Appl Phys Lett. 93 (3), 033310 (2008).</li><li>Li, D., Xia, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrospinning+of+Nanofibers:+Reinventing+the+Wheel?.">Electrospinning of Nanofibers: Reinventing the Wheel?.</a> Adv Mat. 16 (14), 1151-1170 (2004).</li><li>Li, W. J., Laurencin, C. T., Caterson, E. J., Tuan, R. S., Ko, F. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrospun+nanofibrous+structure:+A+novel+scaffold+for+tissue+engineering.">Electrospun nanofibrous structure: A novel scaffold for tissue engineering.</a> J Biomed Mat Res. 60 (4), 613-621 (2002).</li><li>Jia, H., Zhu, G., Vugrinovich, B., Kataphinan, W., Reneker, D. H., Wang, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzyme-Carrying+Polymeric+Nanofibers+Prepared+via+Electrospinning+for+Use+as+Unique+Biocatalysts.">Enzyme-Carrying Polymeric Nanofibers Prepared via Electrospinning for Use as Unique Biocatalysts.</a> Biotechnol Prog. 18 (5), 1027-1032 (2002).</li><li>Mai, L., Xu, L., 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=Electrospun+Ultralong+Hierarchical+Vanadium+Oxide+Nanowires+with+High+Performance+for+Lithium+Ion+Batteries.">Electrospun Ultralong Hierarchical Vanadium Oxide Nanowires with High Performance for Lithium Ion Batteries.</a> Nano Letters. 10 (11), 4750-4755 (2010).</li><li>Cai, J., Niu, 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=High-Performance+Supercapacitor+Electrode+Materials+from+Cellulose-Derived+Carbon+Nanofibers.">High-Performance Supercapacitor Electrode Materials from Cellulose-Derived Carbon Nanofibers.</a> ACS Appl Mat Interfaces. 7 (27), 14946-14953 (2015).</li><li>Joshi, P., Zhang, L., 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=Composite+of+TiO2+nanofibers+and+nanoparticles+for+dye-sensitized+solar+cells+with+significantly+improved+efficiency.">Composite of TiO2 nanofibers and nanoparticles for dye-sensitized solar cells with significantly improved efficiency.</a> Energ Environ Sci. 3 (10), 1507-1510 (2010).</li><li>Macdonald, T. J., Tune, D. D., Dewi, M. R., Gibson, C. T., Shapter, J. G., Nann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+TiO2+Nanofiber-Carbon+Nanotube-Composite+Photoanode+for+Improved+Efficiency+in+Dye-Sensitized+Solar+Cells.">A TiO2 Nanofiber-Carbon Nanotube-Composite Photoanode for Improved Efficiency in Dye-Sensitized Solar Cells.</a> ChemSusChem. 8 (20), 3396-3400 (2015).</li><li>Teo, W. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Electrospinning parameters and fiber control. , (2015).</li></ol>

The methods presented in this work describe the fabrication of efficient nanofibrous photoanodes for photocatalytic devices such as DSSCs. Electrospinning is a very versatile technique for the fabrication of nanofibers, but a certain level of skill and knowledge is required to obtain materials with optimal morphologies. One of the most critical aspects to obtaining good nanofibers is the preparation of the precursor solution: there are some key factors, such as the concentration of the carrier polymer and the choice of t...

Dye-sensitized solar cells (DSSCs) are an interesting alternative to silicon-based solar cells1 thanks to their low cost, relatively simple manufacturing process, and ease of large-scale production. Another benefit is their potential to be incorporated into flexible substrates, a distinct advantage over silicon-based solar cells2. A typical DSSC utilizes: (1) a nanoparticulate TiO2 photoanode, sensitized with a dye, as a light-harvesting layer; (2) a Pt-coated FTO, used as a counter electrode; and (3) an electrolyte containing a redox couple, such as I-/I3-, placed between the two electrodes, working as a &#34;hole-conducting medium.&#34;
Although DSSCs have surpassed efficiencies of 15%3, the performance of nanoparticle-based photoanodes is still still hindered by a number of limitations, including slow electron mobility4, poor absorption of low-energy photons5, and charge recombination6. The electron collection efficiency strongly depends upon the rate of electron transport through the TiO2 nanoparticle layer. If the charge diffusion is slow, the probability of recombination with I3- in the electrolyte solution increases, resulting in a loss of efficiency.
It has been shown that replacing nanoparticulate TiO2 with one-dimensional (1D) TiO2 nanoarchitectures can improve charge transport by reducing the scattering of free electrons from the grain boundaries of the interconnected TiO2 nanoparticles7. As 1D nanostructures provide a more direct pathway for charge collection, we can expect that electron transport in nanofibers (NFs) would be significantly faster than in nanoparticles8,9.
Electrospinning is one of the most commonly used methods for the fabrication of fibrous materials with sub-micron diameters10. This technique involves the use of high voltage to induce the ejection of a polymer solution jet through a spinneret. Due to bending instability, this jet is subsequently stretched many times to form continuous nanofibers. In recent years, this technique has been extensively used to fabricate polymeric and inorganic materials, which have been used for numerous and diverse applications, such as tissue engineering11, catalysis12, and as electrode materials for lithium ion batteries13 and supercapacitors14.
The use of electrospun TiO2-NFs as the scattering layer in the photoanode can increase the performance of DSSCs. However, photoanodes with nanofibrous architectures tend to have poor dye absorption due to surface-area limitations. One of the possible solutions to overcome this is to mix NFs and nanoparticles. This has been shown to result in additional scattering layers, improving light absorption and overall efficiency15.
The protocol presented in this video provides a facile method to synthesize ultralong TiO2 nanofibers through a combination of electrospinning and sol-gel techniques, followed by a calcination process. The protocol then illustrates the use of the TiO2-NFs in combination with nanoparticulate TiO2 for the fabrication of a dual-layer photoanode with enhanced light-scattering capability using doctor blading techniques, as well as the subsequent assembly of a DSSC using such a photoanode.

<table border="0" cellpadding="0" cellspacing="0" width="689">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">titanium(IV) n-butoxide</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">244112</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Polyvinylpyrrolidone</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">437190</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">glacial acetic acid</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td style="width:127px;">A6283</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Ethanol, absolute</td>
			<td style="width:149px;">Fisher Scientific</td>
			<td style="width:127px;">E/0650DF/17</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">20 mL Sample vials</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td>(or larger volume)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">disposable 21G needle</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">P150 grit sandpaper</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">disposable 10mL syringe</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td>(or larger volume)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">magnetic stirrer + stirring bar</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">PHD 2000 syringe pump</td>
			<td style="width:149px;">Harvard Apparatus</td>
			<td style="width:127px;">71-2002</td>
			<td>(or any other syringe pump capable of outputting a 1mL/hr flow</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Aluminium foil</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Stainless steel collector plate</td>
			<td style="width:149px;">(custom built)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:247px;">High Voltage Power Source</td>
			<td style="width:149px;">Gamma High Voltage Research, Inc</td>
			<td style="width:127px;">ES30P-10W</td>
			<td>(or any other power supply capable of outputting +15 kV</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Polycarbonate protective shield</td>
			<td style="width:149px;">(custom built)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Ceramic crucible</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Muffle furnace</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Titanium dioxide, nanopowder</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">718467</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">50 mL 1-neck round bottom flasks</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">bath sonicator</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Terpineol</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Rotary evaporator</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">FTO glass</td>
			<td style="width:149px;">Solaronix</td>
			<td>TCO30-10/LI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Adhesive tape</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">razor blade</td>
			<td style="width:149px;">(any)</td>
			<td style="width:127px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">SEM</td>
			<td style="width:149px;">JEOL</td>
			<td style="width:127px;">6500F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">XRD</td>
			<td style="width:149px;">PANalytical&#160;</td>
			<td style="width:127px;">X&#39;pert Pro</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Titanium Tetrachloride</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">89545</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Ruthenizer&#160; 535-bisTBA</td>
			<td style="width:149px;">Solaronix</td>
			<td style="width:127px;">N719</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">sealing film</td>
			<td style="width:149px;">Dyesol</td>
			<td>Meltonix 1170-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Pt-coated FTO</td>
			<td style="width:149px;">Solaronix</td>
			<td>TCO30-10/LI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1-propyl-3-methylimidazolium iodide</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">49637</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Iodine</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">207772</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">benzimidazole</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">194123</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">3-Methoxypropionitrile</td>
			<td style="width:149px;">Sigma-Aldrich</td>
			<td align="right" style="width:127px;">65290</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Digital source meter</td>
			<td style="width:149px;">Keithley</td>
			<td align="right" style="width:127px;">2400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Solar Simulator</td>
			<td style="width:149px;">Abet technologies</td>
			<td align="right" style="width:127px;">10500</td>
			<td></td>
		</tr>
	</tbody>
</table>

electrospinning of photocatalytic electrodes for dye-sensitized solar cells

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of electrospun titanium dioxide nanofibers (TiO2-NFs) on top of a blocking layer made of commercially available titanium dioxide nanoparticles (TiO2-NPs). This is achieved by first electrospinning a solution of titanium (IV) butoxide, polyvinylpyrrolidone (PVP), and glacial acetic acid in ethanol to obtain composite PVP/TiO2 nanofibers. These are then calcined at 500 &#176;C to remove the PVP and to obtain pure anatase-phase titania nanofibers. This material is characterized using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The photoanode is prepared by first creating a blocking layer through the deposition of a TiO2-NPs/terpineol slurry on a fluorine-doped tin oxide (FTO) glass slide using doctor blading techniques. A subsequent thermal treatment is performed at 500 &#176;C. Then, the light-scattering layer is formed by depositing a TiO2-NFs/terpineol slurry on the same slide, using the same technique, and calcinating again at 500 &#176;C. The performance of the photoanode is tested by fabricating a dye-sensitized solar cell and measuring its efficiency through J-V curves under a range of incident light densities, from 0.25-1 Sun.

The TiO2 nanofibers were characterized using SEM, X-ray photoelectron spectroscopy (XPS), and XRD. The nanostructure of the photoanode was characterized using SEM. The performance of the assembled DSSC was tested using a solar simulator and a source measure unit.
The SEM image in Figure 1A shows that the nanofibers synthesized using this protocol have a porous structure and a high aspect ...

Watch this Scientific Journal Video about Electrospinning of Photocatalytic Electrodes for Dye-sensitized Solar Cells at JoVE.com

Electrospinning of Photocatalytic Electrodes for Dye-sensitized Solar Cells

The overall goal of this project was to use electrospinning to fabricate a photoanode with improved performance for dye-sensitized solar cells.

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of ...

The overall goal of this work is to fabricate a photoanode for dye-sensitized solar cells with improved performance using electrospinning. Nanomaterials are great. They show chemical and physical properties that you cannot find in the corresponding bulk materials.However, if you try to make a device using nanomaterials, this become, can become quite difficult. In this video, we show how to fabricate one-dimensional inorganic nanofibres, and using them for a solar cell device. The directionality in the nanofibres causes the devices to have a much better performance compared with devices that just use nanocrystalline materials.To make the precursor solution, place 10 milliliters of absolute ethanol, one milliliter of glacial acetic acid, five grams of Titanium(II)oxide, and one gram of PVP into a sample vial. Mix the solution until it has become homogeneous and no bubbles can be observed. In order to obtain a one-dimensional nanoarchitecture, we're going to use electrospinning.A simple yet rather clever technique which allows us to obtain nanofibres with several micrometers in length and only few hundred nanometers in diameter. To prepare the needle used for the electrospinning process, cut the tip of a 21 gauge needle and sand it down using moderate grade sandpaper until the tip is completely flat. Load the precursor solution into the syringe and place it on the syringe pump.Wrap the collector plate with aluminum foil and place the protective shield around the setup. The distance between the needle and the collector plate should be 20 centimeters. Connect the collector to the ground and the needle to the power source.Set the flow rate of the syringe pump to one milliliter per hour, and begin pumping. As soon as some solution appears on the tip of the needle, turn on the high voltage source and set it to 15 kilovolts. At this point, fibers are going to collect on the plate.This can be left running for as long as necessary to achieve the desired thickness of the fiber mat. After the spinning is completed, turn off the high voltage source and remove the foil from the collector plate. Letting the fibers rest overnight makes it easier to peel them off the collector plate.Place the peeled off fibers in a crucible and place them in a furnace with a temperature ramp of five degrees per minute, up to 500 degrees for two hours to remove the PVP and produce pure TiO2 nanofibres. Fabrication of the photoanode requires that the position of a light-scattering layer consisting of titanium dioxide nanofibres on top of a blocking layer made of commercially available titanium dioxide nanoparticles. This is essential for preventing charge accumulation with a substrate.Start by adding 500 milligrams of titanium dioxide nanoparticles to 20 mils of ethanol in a round-bottom flask. In a separate flask, mix 500 milligrams of the electrospun titanium dioxide nanofibres with another 20 mils of ethanol. Sonicate the solutions for two hours using a bath sonicator.Once uniform mixtures are obtained, add 2 mils of terpineol to each flask, and sonicate for another 15 minutes. Finally, evaporate the solvent using a rotary evaporator to obtain the slurries. Using a diamond glass cutter, cut an FTO slide into a two by two centimeter square.Place adhesive tape on the glass slide, leaving a 0.4 square centimeter area, exposing the center. Deposit a few drops of the titanium dioxide nanoparticle slurry on the center of the glass slide. Use a razor blade to spread the slurry evenly on the exposed area.Once a uniform coating is achieved, carefully remove the adhesive tape. Photoanodes are then placed in a furnace and centered at 500 degrees for two hours. Repeat the process on the same glass slide, this time using the nanofibre slurry to deposit the light scattering layer.The composite photoanode is again centered at 500 degrees for two hours. To characterize our nanofibres, we are going to use SEM and XRD, and then to test the performance of our nanofibres, we are going to implement them in a dye-sensitized solar cell. To prepare the sample for scanning electron microscoping, attach a strip of adhesive carbon tape on the microscope stub.And then carefully place a small quantity of nanofibres on the tape. Mount the stub onto a sample holder and lower it into the exchange chamber of the instrument. Set up the instrument conditions and parameters accordingly.Collect images of the sample, making sure that they display the overall morphology of the material. The SEM images show that the fibers are porous in structure and have a high aspect ratio. To prepare the material for X-ray diffraction characterization, gently grind some nanofibres into a fine powder and spread them evenly on an XRD stage.Load the sample into the diffractometer. Set up the acquisition parameters and start collecting the data. The diffractogram shows a series of peaks corresponding to the anatase phase of titanium dioxide.To prepare the solar cell, first treat the TiO2 photoanodes with an aqueous solution of TiCl4 at 75 degrees C for 45 minutes. After treatment, wash the photoanodes with the ionized water. Dry them, and insensitize them in a solution of Ruthenizer N719 and absolute ethanol for 24 hours under dark conditions.The sensitized photoanodes will wash with ethanol to remove excess dye molecules from the TiO2 photoanode surface. Sealing film is used as a thermoplastic gasket between the counter electrode and the photoanodes. Counter electrodes of platinum-coated FTO are used for all solar cells.The assembled solar cells are heated to 100 degrees C for 15 minutes to seal the gasket. A redox mediator is added to the internal space of the solar cells by vacuum filling. J-V curves are acquired using a Keithley 2400 Digital SourceMeter under a 100 milowatt per centimeter square illumination from a xenon arc source passed through an AM 1.5 G filter.The illumination plane for the light source is calibrated with a monocrystalline silicon reference cell. In this video, we have shown you how to fabricate a dye-sensitized solar cells using inorganic nanofibres. On top of this application, there are many other possibilities.For example, batteries, transparent electrodes, active filters, and others. If you want to know more details, please have a look at our publications. I hope you enjoyed and learned from this video, and please contact us if you've got question or want to give any feedback.

electrospinning-photocatalytic-electrodes-for-dye-sensitized-solar

Research

JoVE Journal

Engineering

9.5K visualizações.  Victoria University of Wellington. The overall goal of this work is to fabricate a photoanode for dye-sensitized solar cells with improved performance using electrospinning. Nanomaterials are great. They show chemical and physical properties that you cannot find in the corresponding bulk materials.However, if you try to make a device using nanomaterials, this become, can become quite difficult. In this video, we show how to fabricate one-dimensional inorganic nanofibres, and using them for a solar cell device. The direc...