Jiang Ying, Wang Yating, Zhang Zhijie, Dong Zhongliang, Xu Jiayue
School of Materials Science and Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418, P. R. China.
Inorg Chem. 2022 Jul 11;61(27):10557-10566. doi: 10.1021/acs.inorgchem.2c01452. Epub 2022 Jun 26.
The rational design of a two-dimensional (2D)/2D "face-to-face" heterojunction photocatalyst is crucial for the mediation of interfacial charge transfer/separation. Herein, a unique 2D/2D step-scheme (S-scheme) photocatalyst of CsPbBr/BiOCl is constructed by the self-assembly of CsPbBr and BiOCl nanosheets (NSs). Profiting from the effective interface contact and appropriate band structures between CsPbBr and BiOCl NSs, a valid S-scheme heterojunction of CsPbBr/BiOCl is established. Density functional theory (DFT) calculations and a series of characterization techniques including X-ray photoelectron spectra (XPS), photoassisted Kelvin probe force microscopy (KPFM), and electron spin resonance (ESR) systematically corroborate the S-scheme charge-transfer mechanism between CsPbBr and BiOCl. The formation of an S-scheme heterojunction endows the photocatalyst with boosted charge separation and retainment of the highest redox ability. As a result, the obtained 2D/2D CsPbBr/BiOCl S-scheme photocatalyst shows much superior CO-reduction performance to single CsPbBr and BiOCl. This investigation provides new insights into the construction of novel S-scheme heterojunctions based on 2D/2D photocatalytic systems.
二维（2D）/2D“面对面”异质结光催化剂的合理设计对于界面电荷转移/分离的调控至关重要。在此，通过CsPbBr和BiOCl纳米片（NSs）的自组装构建了一种独特的CsPbBr/BiOCl二维/二维阶梯型（S型）光催化剂。得益于CsPbBr和BiOCl NSs之间有效的界面接触和合适的能带结构，建立了有效的CsPbBr/BiOCl S型异质结。密度泛函理论（DFT）计算以及包括X射线光电子能谱（XPS）、光辅助开尔文探针力显微镜（KPFM）和电子自旋共振（ESR）在内的一系列表征技术系统地证实了CsPbBr和BiOCl之间的S型电荷转移机制。S型异质结的形成赋予了光催化剂增强的电荷分离能力，并保留了最高的氧化还原能力。结果，所制备的二维/二维CsPbBr/BiOCl S型光催化剂在CO还原性能方面远优于单一的CsPbBr和BiOCl。本研究为基于二维/二维光催化体系构建新型S型异质结提供了新的见解。
