Key Laboratory for Technology in Rural Water Management of Zhejiang Province, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Int J Environ Res Public Health. 2023 Feb 23;20(5):4009. doi: 10.3390/ijerph20054009.
The efficient, stable, and selective photocatalytic conversion of nitric oxide (NO) into harmless products such as nitrate (NO) is greatly desired but remains an enormous challenge. In this work, a series of BiOI/SnO heterojunctions (denoted as %B-S, where % is the mass portion of BiOI compared with the mass of SnO) were synthesized for the efficient transformation of NO into harmless NO. The best performance was achieved by the 30%B-S catalyst, whose NO removal efficiency was 96.3% and 47.2% higher than that of 15%B-S and 75%B-S, respectively. Moreover, 30%B-S also exhibited good stability and recyclability. This enhanced performance was mainly caused by the heterojunction structure, which facilitated charge transport and electron-hole separation. Under visible light irradiation, the electrons gathered in SnO transformed O to ·O and ·OH, while the holes generated in BiOI oxidized HO to produce ·OH. The abundantly generated ·OH, ·O, and O species effectively converted NO to NO and NO, thus promoting the oxidation of NO to NO. Overall, the heterojunction formation between p-type BiOI and n-type SnO significantly reduced the recombination of photo-induced electron-hole pairs and promoted the photocatalytic activity. This work reveals the critical role of heterojunctions during photocatalytic degradation and provides some insight into NO removal.
高效、稳定、选择性地将一氧化氮（NO）光催化转化为无害产物，如硝酸盐（NO），是人们非常期望的，但这仍然是一个巨大的挑战。在这项工作中，我们合成了一系列 BiOI/SnO 异质结（表示为 %B-S，其中 % 是 BiOI 的质量与 SnO 的质量之比），用于高效地将 NO 转化为无害的 NO。30%B-S 催化剂的性能最佳，其 NO 去除效率分别比 15%B-S 和 75%B-S 催化剂高 96.3%和 47.2%。此外，30%B-S 还表现出良好的稳定性和可循环性。这种增强的性能主要归因于异质结结构，促进了电荷传输和电子-空穴分离。在可见光照射下，聚集在 SnO 中的电子将 O 转化为·O 和·OH，而在 BiOI 中产生的空穴将 HO 氧化生成·OH。大量生成的·OH、·O 和 O 物种有效地将 NO 转化为 NO 和 NO，从而促进了 NO 的氧化。总的来说，p 型 BiOI 和 n 型 SnO 之间的异质结形成显著减少了光生电子-空穴对的复合，并促进了光催化活性。这项工作揭示了异质结对光催化降解过程的关键作用，并为 NO 去除提供了一些见解。
