Carbon decorated In2O3/TiO2 heterostructures with enhanced visible-light-driven photocatalytic activity
Carbon decorated In2O3/TiO2 heterostructures with enhanced visible-light-driven photocatalytic activity
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DOI：
10.1016/j.jcat.2017.09.006
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发表时间：
2017-11
影响因子：
7.3
通讯作者：
Xiao Zhou;Jiang Wu;Qifen Li;T. Zeng;Zheng Ji;P. He;W. Pan;Xuemei Qi;Chengyao Wang
中科院分区：
文献类型：
--
作者：
Xiao Zhou;Jiang Wu;Qifen Li;T. Zeng;Zheng Ji;P. He;W. Pan;Xuemei Qi;Chengyao Wang
二氧化钛（TiO 2）是解决环境污染和能源危机的理想材料，但其禁带宽度大，电荷结合率高，阻碍了其应用。缩小禁带宽度和提高光生电子-空穴对的分离仍然是一个具有挑战性的课题。在不同物质之间产生异质结是一种有效的方法。同时，碳掺杂是一种有效的减小带隙、促进电荷转移的技术。本研究采用湿浸渍法制备了碳修饰的In 2 O3/TiO 2异质结构。碳掺杂使TiO 2在价带（VB）以上产生额外的碳掺杂水平，使其在可见光下被激发，并在In 2 O3和TiO 2之间形成异质结，抑制了光激发电子和空穴的复合，促进了界面电荷的迁移。此外，三元纳米复合材料表现出光生电子和空穴的有效分离和迁移性能，在可见光照射下光催化去除单质汞（Hg 0）时表现出比纯P25更强的光催化活性。根据表征和实验结果，提出了可能的电荷转移和光催化反应机理。鉴于所制备的样品的光催化性能的增强，碳和In 2 O3的组合掺杂到TiO 2载体是一个很有前途的方法，以提高光催化活性。同时，该方法对新型高效光催化剂的设计、制备和大规模工业应用具有极大的帮助。
Titanium dioxide (TiO2) has been observed to solve environmental pollution and energy crisis, but its large band gap and high rate of charges combination impede its application. Narrowing band gap and enhancing separation of photoinduced electron-hole pairs are still a challenging task. Creating the heterojunction between different substances is an effective method. Meanwhile, doping TiO2with carbon is an efficient technique to reduce band gap and facilitate charges’ transfer. In this study, carbon modified In2O3/TiO2heterostructures are prepared via a facile incipient wet impregnation method. Doping TiO2with carbon produces an additional carbon-doping level above valence band (VB) of TiO2causing it to be excited under visible light, and forms heterojunction between In2O3and TiO2, which suppresses recombination of photoexcited electrons and holes and promotes migration of charge at the interface. Furthermore, ternary nanocomposite exhibits an effective separation and migration performance of photoinduced electrons and holes, and it shows enhanced photoactivity compared with pure P25 when it is applied to photocatalytically remove elemental mercury (Hg0) under visible light irradiation. The possible charge transfer and photocatalytic reaction mechanism are proposed based on characterization and experimental results. In view of the enhanced photocatalytic performance of as-prepared sample, combination of carbon and In2O3doped into TiO2support is a promising method to improve the photoactivity. Meanwhile, this method has a tremendous assist on designing and preparing newly effective photocatalyst and large-scale industrial applications.