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 TiO₂ with carbon is an efficient technique to reduce band gap and facilitate charges’ transfer. In this study, carbon modified In₂O₃/TiO₂ heterostructures are prepared via a facile incipient wet impregnation method. Doping TiO₂ with carbon produces an additional carbon-doping level above valence band (VB) of TiO₂ causing it to be excited under visible light, and forms heterojunction between In₂O₃ and 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 In₂O₃ doped into TiO₂ support 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.

已经观察到二氧化钛（TiO ₂）解决了环境污染和能源危机，但是其大的带隙和高的电荷率组合阻碍了其应用。缩小带隙和增强光致电子-空穴对的分离仍然是一项艰巨的任务。在不同物质之间创建异质结是一种有效的方法。同时，用碳掺杂TiO ₂是减少带隙并促进电荷转移的有效技术。在这项研究中，碳改性的In ₂ O ₃ / TiO ₂异质结构是通过一种简便的湿法浸渍法制备的。掺杂TiO ₂碳会产生高于TiO ₂价带（VB）的额外碳掺杂水平，使其在可见光下被激发，并在In ₂ O ₃和TiO ₂之间形成异质结，从而抑制光激发电子与空穴的复合并促进迁移接口上的充电。此外，三元纳米复合材料表现出有效的光致电子和空穴的分离和迁移性能，与纯P25相比，当其用于光催化去除元素汞（Hg ⁰）在可见光照射下。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。考虑到所制备样品的增强的光催化性能，将碳和In ₂ O ₃掺杂到TiO ₂载体中的组合是改善光活性的一种有前途的方法。同时，该方法在设计和制备新型有效的光催化剂和大规模工业应用方面具有极大的帮助。