双功能电抗滤波器，可同时进行 Sb（III）氧化和固存
Summary
介绍了由碳纳米管和钛酸纳米线组成的双功能电活性滤波器的合理设计方案，并介绍了其在Sb（III）氧化和固存中的环境应用。
Abstract
我们设计了一种简单的方法来合成由两种一维材料组成的双功能电化学过滤器：钛金属纳米线和碳纳米管。混合钛酸-CNT过滤器由声波结合过滤后路线制备。由于暴露吸附位数量的增加的协同效应，电化学反应性、钛酸-CNT 网络的小孔径以及流通设计，同时 Sb（III） 氧化和固存很容易实现。原子荧光光谱仪技术表明，应用电场加速了Sb（III）转换速率，而由于钛酸盐纳米线具有Sb特异性，其获得Sb（V）被有效地吸附。该协议为去除剧毒Sb（III）和其他类似的重金属离子提供了实用的解决方案。
Introduction
近来，由新兴氧化毒（Sb）引起的环境污染引起了人们的广泛关注。广泛的研究表明，Sb化合物对人类和微生物具有高毒性，尽管存在于低浓度的环境中3，4。更糟糕的是，传统的物理化学或生物方法通常由于低浓度和高毒性5而对去除这些新出现的污染物无效。最丰富的Sb（V）和Sb（III）物种，后者的毒性更大。
在目前可用的治疗方法中，吸附被认为是一种有前途的可行替代品，由于其高效率、低成本和简单性6，7。到目前为止，已经开发出了几个纳米级吸附剂，具有可调微结构、大特异性和Sb特异性，如TiO28、MnO29、钛酸10、零价铁11、氧化铁等二元金属氧化物12、13。处理纳米级吸附剂时，一个常见问题是分离后问题，因为其颗粒尺寸小。解决这个问题的一个策略是将这些纳米吸附剂加载到宏观/微尺度支持14。另一个限制吸附技术广泛应用的具有挑战性的问题是，目标化合物/分子浓度有限导致质量运输不良。这个问题可以通过采用膜设计和公约来部分解决，可以显著提高大众运输。最近，人们一直在努力开发先进的处理系统，将吸附和氧化结合在一个单元中，以便有效去除Sb（III）。在这里，我们展示了电活性钛碳纳米管（钛酸-CNT）过滤器是如何合理设计和应用于同时吸附和固存有毒Sb（III）的。通过微调钛酸盐载荷量、施加电压和流速，我们展示了如何相应地定制Sb（III）氧化速率和固存效率。虽然电活性滤波器的制造和应用在本协议中显示，类似的设计也适用于其他重金属离子的处理。
制造过程和试剂的微小变化可能导致最终系统的形态和性能发生重大变化。例如，热液时间、温度和化学纯度已证明会影响这些纳米级吸附剂的微观结构。吸附液的流速也决定了流通系统中的停留时间以及目标化合物的去除效率。通过明确识别这些关键影响参数，可以保证可重复的合成协议，并实现Sb（III）的稳定去除效率。该协议旨在提供有关双功能混合过滤器制造及其在通过流式去除有毒重金属离子方面的应用的详细经验。
Protocol
Representative Results
Discussion
该技术的关键是制造具有高 Sb 特异性的电活性导电和多孔混合滤波器。为此，应特别注意制造过程。由于滤波器的导电性和表面积之间存在”权衡”效应，因此需要精确控制钛酸纳米线的数量。
此外，还应注意，需要适当的电压。一旦施加的电压过高（例如，>3 V），其他竞争反应（如水分裂）可能导致电极表面产生大量气泡（阳极处的O2和阴极处的H2），这可?…
Declarações
The authors have nothing to disclose.
Acknowledgements
这项工作得到了中国上海市自然科学基金（第18ZR1401000号）、上海浦江计划（第18PJ1400400）和国家重点研究与开发项目（第2018YFF0215703号）的支持。
Materials
| Atomic fluorescence spectrometer | Ruili Co., Ltd | ||
| Carbon nanotubes (CNT) | TimesNano Co., Ltd | ||
| DC power supply | Dahua Co., Ltd | ||
| Ethanol, 96% | Sinopharm | ||
| Hydrochloric acid, 36% | Sinopharm | Corrosive | |
| L-antimony potassium tartrate | Sigma-Aldrich | Highly toxic | |
| N-methyl-2-pyrrolidinone (NMP), 99.5% | Sinopharm | Highly toxic | |
| Potassium hydroxide, 85% | Sinopharm | Corrosive | |
| Peristaltic pump | Ismatec Co., Ltd | ||
| Titanium dioxide powders | Sinopharm |
Referências
- Sun, W. M., et al. Profiling microbial community in a watershed heavily contaminated by an active antimony (Sb) mine in Southwest China. Science of the Total Environment. 550, 297-308 (2016).
- Herath, I., Vithanage, M., Bundschuh, J. Antimony as a global dilemma: geochemistry, mobility, fate and transport. Environmental Pollution. 223, 545-559 (2017).
- Pan, L. B., et al. Assessments of levels, potential ecological risk, and human health risk of heavy metals in the soils from a typical county in Shanxi Province, China. Environmental Science and Pollution Research. 23, 19330-19340 (2016).
- Huang, S. S., et al. Sulfide-modified zerovalent iron for enhanced antimonite sequestration: characterization, performance, and reaction mechanisms. Chemical Engineering Journal. 338, 539-547 (2018).
- Ungureanu, G., Santos, S., Boaventura, R., Botelho, C. Arsenic and antimony in water and wastewater: Overview of removal techniques with special reference to latest advances in adsorption. Journal of Environmental Management. 151, 326-342 (2015).
- Zou, J. P., et al. Three-dimensional reduced graphene oxide coupled with Mn3O4 for highly efficient removal of Sb(III) and Sb(V) from water. Acs Applied Materials & Interfaces. 8, 18140-18149 (2016).
- Saleh, T. A., Sari, A., Tuzen, M. Effective adsorption of antimony(III) from aqueous solutions by polyamide-graphene composite as a novel adsorbent. Chemical Engineering Journal. 307, 230-238 (2017).
- Yan, Y. Z., An, Q. D., Xiao, Z. Y., Zheng, W., Zhai, S. G. Flexible core-shell/bead-like alginate@PEI with exceptional adsorption capacity, recycling performance toward batch and column sorption of Cr(VI). Chemical Engineering Journal. 313, 475-486 (2017).
- Fu, L., Shozugawa, K., Matsuo, M. Oxidation of antimony (III) in soil by manganese (IV) oxide using X-ray absorption fine structure. Journal of Environmental Sciences. 73, 31-37 (2018).
- Liu, W., et al. Adsorption of Pb2+, Cd2+, Cu2+ and Cr3+ onto titanate nanotubes: competition and effect of inorganic ions. Science of the Total Environment. 456, 171-180 (2013).
- Wu, B., et al. Dynamic study of Cr(VI) removal performance and mechanism from water using multilayer material coated nanoscale zerovalent iron. Environmental Pollution. 240, 717-724 (2018).
- Shan, C., Ma, Z. Y., Tong, M. P. Efficient removal of trace antimony(III) through adsorption by hematite modified magnetic nanoparticles. Journal of Hazardous Materials. 268, 229-236 (2014).
- Luo, J. M., et al. Removal of antimonite (Sb(III)) and antimonate (Sb(V)) from aqueous solution using carbon nanofibers that are decorated with zirconium oxide (ZrO2). Environmental Science & Technology. 49, 11115-11124 (2015).
- Liu, Y. B., et al. Golden carbon nanotube membrane for continuous flow catalysis. Industrial & Engineering Chemistry Research. 56, 2999-3007 (2017).
- Ma, B. W., et al. Enhanced antimony(V) removal using synergistic effects of Fe hydrolytic flocs and ultrafiltration membrane with sludge discharge evaluation. Water Research. 121, 171-177 (2017).
- Yuan, Z. Y., Zhang, X. B., Su, B. L. Moderate hydrothermal synthesis of potassium titanate nanowires. Applied Physics a-Materials Science & Processing. 78, 1063-1066 (2004).
- Liu, Y. B., et al. Electroactive modified carbon nanotube filter for simultaneous detoxification and sequestration of Sb(III). Environmental Science & Technology. 53, 1527-1535 (2019).
- Gao, G., Vecitis, C. D. Electrochemical carbon nanotube filter oxidative performance as a function of surface chemistry. Environmental Science & Technology. 45, 9726-9734 (2011).
- Liu, Y. B., et al. Simultaneous oxidation and sorption of highly toxic Sb(III) using a dual-functional electroactive filter. Environmental Pollution. 251, 72-80 (2019).
