This work was supported by the Natural Science Foundation of Shanghai, China (No. 18ZR1401000), the Shanghai Pujiang Program (No. 18PJ1400400), and the National Key Research and Development Program of China (No. 2018YFF0215703).

CAUTION: Please carefully read relevant safety data sheets (SDS) of all chemicals and wear proper personal protection equipment (PPE) before use. Some of the chemicals are toxic and irritant. Be careful when handling carbon nanotubes, which may have additional hazards if inhaled or contacted by skin.
1. Preparation of the electroactive titanate-CNT filter
<ol>
	<li>Preparation of titanate nanowires16
	<ol>
		<li>Dissolve 56 g of potassium hydroxide (K...

<ol>
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G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexible+core-shell/bead-like+alginate@PEI+with+exceptional+adsorption+capacity,+recycling+performance+toward+batch+and+column+sorption+of+Cr(VI).">Flexible core-shell/bead-like alginate@PEI with exceptional adsorption capacity, recycling performance toward batch and column sorption of Cr(VI).</a> Chemical Engineering Journal. 313, 475-486 (2017).</li><li>Fu, L., Shozugawa, K., Matsuo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidation+of+antimony+(III)+in+soil+by+manganese+(IV)+oxide+using+X-ray+absorption+fine+structure.">Oxidation of antimony (III) in soil by manganese (IV) oxide using X-ray absorption fine structure.</a> Journal of Environmental Sciences. 73, 31-37 (2018).</li><li>Liu, 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=Adsorption+of+Pb2+,+Cd2+,+Cu2++and+Cr3++onto+titanate+nanotubes:+competition+and+effect+of+inorganic+ions.">Adsorption of Pb2+, Cd2+, Cu2+ and Cr3+ onto titanate nanotubes: competition and effect of inorganic ions.</a> Science of the Total Environment. 456, 171-180 (2013).</li><li>Wu, B., 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=Dynamic+study+of+Cr(VI)+removal+performance+and+mechanism+from+water+using+multilayer+material+coated+nanoscale+zerovalent+iron.">Dynamic study of Cr(VI) removal performance and mechanism from water using multilayer material coated nanoscale zerovalent iron.</a> Environmental Pollution. 240, 717-724 (2018).</li><li>Shan, C., Ma, Z. Y., Tong, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+removal+of+trace+antimony(III)+through+adsorption+by+hematite+modified+magnetic+nanoparticles.">Efficient removal of trace antimony(III) through adsorption by hematite modified magnetic nanoparticles.</a> Journal of Hazardous Materials. 268, 229-236 (2014).</li><li>Luo, 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=Removal+of+antimonite+(Sb(III))+and+antimonate+(Sb(V))+from+aqueous+solution+using+carbon+nanofibers+that+are+decorated+with+zirconium+oxide+(ZrO2).">Removal of antimonite (Sb(III)) and antimonate (Sb(V)) from aqueous solution using carbon nanofibers that are decorated with zirconium oxide (ZrO2).</a> Environmental Science &amp; Technology. 49, 11115-11124 (2015).</li><li>Liu, Y. B., 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=Golden+carbon+nanotube+membrane+for+continuous+flow+catalysis.">Golden carbon nanotube membrane for continuous flow catalysis.</a> Industrial &amp; Engineering Chemistry Research. 56, 2999-3007 (2017).</li><li>Ma, B. 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=Enhanced+antimony(V)+removal+using+synergistic+effects+of+Fe+hydrolytic+flocs+and+ultrafiltration+membrane+with+sludge+discharge+evaluation.">Enhanced antimony(V) removal using synergistic effects of Fe hydrolytic flocs and ultrafiltration membrane with sludge discharge evaluation.</a> Water Research. 121, 171-177 (2017).</li><li>Yuan, Z. Y., Zhang, X. B., Su, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Moderate+hydrothermal+synthesis+of+potassium+titanate+nanowires.">Moderate hydrothermal synthesis of potassium titanate nanowires.</a> Applied Physics a-Materials Science &amp; Processing. 78, 1063-1066 (2004).</li><li>Liu, Y. B., 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=Electroactive+modified+carbon+nanotube+filter+for+simultaneous+detoxification+and+sequestration+of+Sb(III).">Electroactive modified carbon nanotube filter for simultaneous detoxification and sequestration of Sb(III).</a> Environmental Science &amp; Technology. 53, 1527-1535 (2019).</li><li>Gao, G., Vecitis, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+carbon+nanotube+filter+oxidative+performance+as+a+function+of+surface+chemistry.">Electrochemical carbon nanotube filter oxidative performance as a function of surface chemistry.</a> Environmental Science &amp; Technology. 45, 9726-9734 (2011).</li><li>Liu, Y. B., 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=Simultaneous+oxidation+and+sorption+of+highly+toxic+Sb(III)+using+a+dual-functional+electroactive+filter.">Simultaneous oxidation and sorption of highly toxic Sb(III) using a dual-functional electroactive filter.</a> Environmental Pollution. 251, 72-80 (2019).</li></ol>

We have nothing to disclose.

The key to this technology is to fabricate an electroactive conductive and porous hybrid filter with high Sb-specificity. To do this, special care should be paid to the fabrication process. The amount of titanate nanowires need to be precisely controlled due to the "trade-off" effect between the filter's electrical conductivity and surface area.
In addition, it should be also noted that a proper applied voltage is necessary. Once the applied voltage is too high (e.g., &#62;3 V), other competit...

Recently, the environmental pollution caused by emerging antimony (Sb) has attracted much attention1,2. Extensive studies demonstrate that Sb compounds pose high toxicity to human and microorganisms, although present in low concentrations in the environment3,4. Even worse, conventional physicochemical or biological methods are usually ineffective to remove these emerging contaminants due to their low concentrations and high toxicity5. The most abundant species of Sb are Sb(V) and Sb(III), of which the latter form is more toxic.
Among the currently available treatment methods, adsorption is believed to be a promising and feasible alternative due to its high efficiency, low cost, and simplicity6,7. Till now, several nanoscale sorbents with tunable microstructures, large specific surface area and Sb specificity have been developed, such as TiO28, MnO29, titanate10, zerovalent iron11, iron oxides and other binary metal oxides12,13. A common problem when dealing with nanoscale adsorbents is the post-separation issue due to their small particle size. One strategy to address this issue is to load these nano-sorbents onto macro/micro-scale supports14. Another challenging issue restricting the wide application of adsorption technology is the poor mass transport caused by limited concentration of target compounds/molecules15. This issue may be partially addressed by adopting a membrane design and convention could enhance the mass transport significantly. Recent efforts have been devoted to develop advanced treatment systems that combine adsorption and oxidation in a single unit for effective Sb(III) removal. Here, we show how an electroactive titanate-carbon nanotube (titanate-CNT) filter was rationally designed and applied for the simultaneously adsorption and sequestration of toxic Sb(III). By fine-tuning the titanate loading amount, applied voltage, and flow rate, we demonstrate how the Sb(III) oxidation rate and sequestration efficiency can be tailored correspondingly. Although the fabrication and application of the electroactive filter is shown in this protocol, similar designs can also apply to the treatment of other heavy metal ions.
Minor changes in the fabrication process and reagents may cause significant changes in the morphology and performance of the final system. For instance, the hydrothermal time, temperature, and chemical purity have been shown to affect the microstructures of these nanoscale adsorbents. The flow rate of the adsorbate solution also determines the residence time within a flow-through system as well as the removal efficiency of target compounds. With clear identification of these key impacting parameters, a reproducible synthesis protocol can be secured and a stable removal efficiency of Sb(III) can be achieved. This protocol aims to provide detailed experience on the fabrication of dual-functional hybrid filters as well as their applications towards the removal of toxic heavy metal ions in a flow-through manner.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Atomic fluorescence spectrometer</td>
			<td>Ruili Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon nanotubes (CNT)</td>
			<td>TimesNano Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DC power supply</td>
			<td>Dahua Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol, 96%</td>
			<td>Sinopharm</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid, 36%</td>
			<td>Sinopharm</td>
			<td></td>
			<td>Corrosive</td>
		</tr>
		<tr>
			<td>L-antimony potassium tartrate</td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td>Highly toxic</td>
		</tr>
		<tr>
			<td>N-methyl-2-pyrrolidinone (NMP), 99.5%</td>
			<td>Sinopharm</td>
			<td></td>
			<td>Highly toxic</td>
		</tr>
		<tr>
			<td>Potassium hydroxide, 85%</td>
			<td>Sinopharm</td>
			<td></td>
			<td>Corrosive</td>
		</tr>
		<tr>
			<td>Peristaltic pump</td>
			<td>Ismatec Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Titanium dioxide powders</td>
			<td>Sinopharm</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

a dual-functional electroactive filter towards simultaneously sb(iii) oxidation and sequestration

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon nanotubes. The hybrid titanate-CNT filter was prepared by a sonication coupled with a post-filtration route. Due to the synergistic effects of the increased number of exposed sorption sites, electrochemical reactivity, small pore size of the titanate-CNT network coupled with a flow-through design, simultaneous Sb(III) oxidation and sequestration can be readily achieved. Atomic fluorescence spectrometer technology demonstrated that the applied electrical field accelerates the Sb(III) conversion rate and the as-obtained Sb(V) were adsorbed effectively by the titanate nanowires due to their Sb specificity. This protocol provides a practical solution for the removal of highly toxic Sb(III) and other similar heavy metal ions.

The electroactive filtration apparatus employed is an electrochemically modified polycarbonate filtration casing (Figure 1). Field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM) techniques are employed to characterize the morphology of the titanate-CNT filter (Figure 2). To demonstrate the efficacy of the electrochemical filtration system, the change of Sbtotal and Sb valence state as a function of time is det...

Watch this Scientific Journal Video about A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration at JoVE.com

A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration

A protocol for the rational design of a dual-functional electroactive filter consisting of carbon nanotubes and titanate nanowires is reported and their environmental applications towards Sb(III) oxidation and sequestration is presented.

A Dual-Functional Electroactive Filter Towards Simultaneously Sb(III) Oxidation and Sequestration

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon ...

A removal of emerging contaminant antimony from surface waters is highly demanded. The most abundant antimony species are antimony three and antimony five, and antimony three is 10 times more toxic than antimony five. A two-step oxidation precipitation strategy is commonly adopted for antimony three removal, that is to oxidize antimony three to antimony five firstly, followed by chemical precipitation.But we could achieve this within a single unit. Since antimony shares similar physical chemical properties with other elements from the same nitrogen group, like arsenic or phosphorus, I believe this method could also be extended to these compounds. Be sure to read the SDS of all of the chemicals carefully.Follow the protocol and the incumbent instructions closely, and learn how to differentiate between antimony three and five. Minor changes in the protocol may cause significant changes in the system performance. For example, too much titanate may deter your rate of conductivity and antimony three removal kinetics of the filter.To prepare the titanate nano wires, first dissolve 56 grams of potassium hydroxide in 100 milliliters of de-ionized water under vigorous stirring. Next add 3 grams of titanium dioxide powder to the solution. Entrance for the solution into a Teflon lined reactor.Hold the solution at 200 degrees Celsius for 24 hours. Before washing the resulting white precipitate with 0.1 mols per liter of hydraulic acid and de-ionized water, until a neutral affluent pH is obtained. Dry the product under vacuum at 60 degrees Celsius overnight.Then transfer the product to a tube furnace and heat the material to 600 degrees Celsius for 2 hours with a ramp rate of 1 degree Celsius per minute. For titanate CNT filter preparation, add 20 milligrams of CNT's into 40 milliliters of N-Methyl pyrrolidone and probe sonicate the mixture for 40 minutes to obtain a homogenous solution. Next add 200 milligrams of the titanate nano wires to 20 milliliters of methyl pyrrolidone and probe sonicate the mixture for 20 minutes.At the end of the sonication, mix the titanate dispersion solution with the CNT dispersion solution and filter the resulting mixture onto a PTFE membrane. Then rinse the filter one time with 100 milliliters of ethanol, and one time with 200 milliliters of de-ionized water. For electrochemical antimony filtration, first add 2.2 milligrams of potassium antimonyl tartrate trihydrate to 1, 000 milliliters of de-ionized water before adding 100 milliliters of the resulting 800 micrograms per liter antimony solution to a 150 milliliter beaker.Adjust the solution to a pH of 7, and place the prepared titanate CNT filter anode into an electrochemistry modified polycarbonate filtration casing. Place a CNT-alone filter into the casing as the cathode, and connect the anode and cathode with a perforated titanium ring. Use insulating silicone rubber to separate and seal the casing, and pass the antimony solution through the filtration system at an appropriate flow rate, using a DC power supply to apply the correct voltage during the filtration.At the end of the filtration, use an atomic fluorescent spectrometer to determine the total antimony and antimony three concentrations according to standard protocols. The electro active filtration apparatus is an electrochemically modified polycarbonate filtration casing. Field emission scanning electron microscope images of the titanate CNT filter suggest a roughened surface.Transmission electron microscopy characterization suggests that the CNT's are entangled with the titanate nano wires after processing, indicating a successful synthesis of the titanate-CNT hybrid material. To demonstrate the efficacy of the electrochemical filtration system, the change of the antimony total and the antimony valence state as a function of time can be determined. For example, in this representative analysis, the antimony five concentration rose sharply within the initial 30 minutes.While a complete antimony three conversion was observed over 1 hour of continuous filtration in the recirculation mode, indicating the antimony three oxidation was the main reaction process in the initial stage, allowing the antimony five to be absorbed effectively by the loaded titanate nano wires. Furthermore, both the antimony sorption kinetics and capacity increased with the applied voltage due to the enhanced electrostatic interactions and near the surface transport by electro migration. This protocol is dedicated to provide a promising strategy by integrating complicated tasks, membrane science, and electro-chemistry for the decontamination of antimony three and other similar components in water.Using the fabricated filter as a cathode filtration system at the function or reduction and absorption may be demonstrated. Allowing the decontamination of other heavy metal ions like chromium six. In the next step we plan to investigate the impact of natural organic materials on the antimony three removal performance as well as dedicated to develop lab features to achieve improved kinetics.Some of the chemicals are toxic, corrosive, or irritants. Be sure to always wear the appropriate personal protection equipment during their use.

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5.4K 조회수.  Donghua University. 표면 물에서 새로운 오염 물질 항mony의 제거가 매우 요구된다. 가장 풍부한 항문종은 항문3종과 항문5종이며, 항문3종은 항문5종보다 10배 더 독성이 있다. 2단계 산화 강수전략은 일반적으로 항문 3개 제거를 위해 채택되며, 이는 항문3을 먼저 산화하고 화학강수량이 뒤따릅니다.그러나 우리는 하나의 단위 내에서이를 달성 할 수 있습니다. 항문은 비소 또는 인과 같은 동...