Liu Chao, Xiao Wen, Yu Guiyun, Wang Qiang, Hu Jiawei, Xu Chenghao, Du Xinyi, Xu Jianguang, Zhang Qinfang, Zou Zhigang
School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, PR China.
School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, PR China.
J Colloid Interface Sci. 2023 Jun 15;640:851-863. doi: 10.1016/j.jcis.2023.02.137. Epub 2023 Feb 28.
Developing efficient heterojunction photocatalysts that have a high charge carrier separation rate and improved light-harvesting capacity is a crucial step in solving energy crisis and reducing environmental pollution. Herein, we synthesized few-layered TiC MXene sheets (MXs) by a manual shaking process, and combined with CdInS (CIS) to construct novel TiC MXene/CdInS (MXCIS) Schottky heterojunction through a solvothermal method. The strong interface between two-dimensional (2D) TiC MXene and 2D CIS nanoplates led to enhanced light-harvesting capacity and promoted charge separation rate. Additionally, the presence of S vacancies on the MXCIS surface helped to trap free electrons. The optimal sample, 5-MXCIS (with 5 wt% MXs loading), exhibited outstanding performance for photocatalytic hydrogen (H) evolution and Cr(VI) reduction under visible light due to the synergistic effect of enhanced light-harvesting capacity and charge separation rate. The charge transfer kinetics was thoroughly studied using multiple techniques. The reactive species of O, OH and h were generated in 5-MXCIS system, and e and O radicals were found to be the main contributors to Cr(VI) photoreduction. Based on the characterization results, a possible photocatalytic mechanism for H evolution and Cr(VI) reduction was proposed. On the whole, this work provides new insights into the design of 2D/2D MXene-based Schottky heterojunction photocatalysts for boosting photocatalytic efficiency.
开发具有高电荷载流子分离率和提高光捕获能力的高效异质结光催化剂是解决能源危机和减少环境污染的关键一步。在此，我们通过手动振荡过程合成了少层TiC MXene片（MXs），并与CdInS（CIS）结合，通过溶剂热法构建了新型TiC MXene/CdInS（MXCIS）肖特基异质结。二维（2D）TiC MXene和2D CIS纳米片之间的强界面导致光捕获能力增强和电荷分离率提高。此外，MXCIS表面存在的S空位有助于捕获自由电子。最佳样品5-MXCIS（MXs负载量为5 wt%）由于光捕获能力增强和电荷分离率的协同作用，在可见光下表现出优异的光催化析氢（H）和还原Cr（VI）的性能。使用多种技术对电荷转移动力学进行了深入研究。在5-MXCIS体系中产生了O、OH和h等活性物种，发现e和O自由基是Cr（VI）光还原的主要贡献者。基于表征结果，提出了一种可能的析氢和还原Cr（VI）的光催化机理。总体而言，这项工作为设计用于提高光催化效率的二维/二维MXene基肖特基异质结光催化剂提供了新的见解。
