Luo Pei-Pei, Zhou Xin-Ke, Li Yu, Lu Tong-Bu
MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin 300384, China.
ACS Appl Mater Interfaces. 2022 May 11;14(18):21069-21078. doi: 10.1021/acsami.2c03671. Epub 2022 Apr 29.
Solar energy-driven direct CH conversion to liquid oxygenates provides a promising avenue toward green and sustainable CH industry, yet still confronts issues of low selectivity toward single oxygenate and use of noble-metal cocatalysts. Herein, for the first time, we report a defect-engineering strategy that rationally regulates the defective layer over TiO for selective aerobic photocatalytic CH conversion to HCHO without using noble-metal cocatalysts. (Photo)electrochemical and in situ EPR/Raman spectroscopic measurements reveal that an optimized oxygen-vacancy-rich surface disorder layer with a thickness of 1.37 nm can simultaneously promote the separation and migration of photogenerated charge carriers and enhance the activation of O and CH, respectively, to •OH and •CH radicals, thereby synergistically boosting HCHO production in aerobic photocatalytic CH conversion. As a result, a HCHO production rate up to 3.16 mmol g h with 81.2% selectivity is achieved, outperforming those of the reported state-of-the-art photocatalytic systems. This work sheds light on the mechanism of O-participated photocatalytic CH conversion on defective metal oxides and expands the application of defect engineering in designing low-cost and efficient photocatalysts.
太阳能驱动的直接CH转化为液态含氧化合物为绿色可持续的CH工业提供了一条有前景的途径，但仍面临对单一含氧化合物选择性低以及使用贵金属助催化剂的问题。在此，我们首次报道了一种缺陷工程策略，该策略合理调控TiO上的缺陷层，用于在不使用贵金属助催化剂的情况下将CH选择性有氧光催化转化为HCHO。（光）电化学和原位EPR/拉曼光谱测量表明，厚度为1.37 nm的优化富氧空位表面无序层可同时促进光生电荷载流子的分离和迁移，并分别增强O和CH向•OH和•CH自由基的活化，从而协同提高有氧光催化CH转化中HCHO的产量。结果，实现了高达3.16 mmol g h的HCHO产率和81.2%的选择性，优于已报道的最先进光催化系统。这项工作揭示了缺陷金属氧化物上O参与的光催化CH转化机制，并扩展了缺陷工程在设计低成本高效光催化剂方面的应用。
