Abstract:

Nitrogen oxides (NO_x) are a type of harmful air pollutants that can cause serious environmental problems such as acid rain, haze, and photochemical smog. At present, how to effectively remove the low concentration of NO_x in the air (ppb level: one part per billion) is a research hotspot and difficulty. The semiconductor photocatalytic oxidation method can oxidize low concentration NO_x in the air into non-toxic nitrate, which is one of the economic and effective purification technologies. This review article mainly focuses on three types of semiconductor photocatalytic materials, such as titanium dioxide (TiO₂), carbon nitride (g-C₃N₄) and Bi-based semiconductors, and provides a brief overview of their research on the photocatalytic removal of low-concentration NO_x in recent years. Meanwhile, various representative works introduce the modification strategies of noble metal deposition, element doping, semiconductor combination and surface vacancy defect engineering to improve the photocatalytic performance of semiconductor materials in removing low concentrations NO_x. In order to provide ideas for the rational design and preparation of high-performance semiconductor photocatalysts and the exploration of catalytic mechanisms, the future development of semiconductor materials in photocatalytic low concentration NO_x is finally prospected.

Key words: semiconductor materials, photocatalysis, low concentration, nitrogen oxides

摘要：

氮氧化物（NO_x）是一类有害的空气污染物，会引发酸雨、雾霾、光化学烟雾等严重的环境问题。目前，如何有效地去除空气中低浓度的NO_x（十亿分之一）是研究的热点和难点。半导体光催化氧化法可以将空气中低浓度NO_x氧化成无毒的硝酸盐，是一种经济有效的净化技术之一。本文主要围绕二氧化钛（TiO₂），氮化碳（g-C₃N₄）和Bi系三类半导体光催化材料，对近年来包括本课题组在内的国内外对光催化去除低浓度NO_x研究进行了简要概述。其中，通过代表性的工作介绍了贵金属沉积、元素掺杂、构建异质结和表面空位缺陷工程等改性策略，以提高半导体材料在去除低浓度NO_x的光催化活性和性能。此外，对半导体材料在光净化低浓度NO_x的未来发展进行了展望，以期待为高性能半导体光催化剂的理性设计和制备以及催化机理的探索等方面的研究提供思路。

关键词: 半导体材料, 光催化, 低浓度, 氮氧化物