TiO2/CsPbBr3 S-scheme heterojunctions with highly improved CO2 photoreduction activity through facet-induced Fermi level modulation

Lanxin Wang; Jinyu Qiu; Nan Wu; Xuelian Yu; Xiaoqiang An

doi:10.1016/j.jcis.2022.08.120

TiO₂/CsPbBr₃ S-scheme heterojunctions with highly improved CO₂ photoreduction activity through facet-induced Fermi level modulation

J Colloid Interface Sci. 2023 Jan;629(Pt A):206-214. doi: 10.1016/j.jcis.2022.08.120. Epub 2022 Aug 20.

Authors

Lanxin Wang¹, Jinyu Qiu¹, Nan Wu¹, Xuelian Yu¹, Xiaoqiang An²

Affiliations

¹ Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, 100083 Beijing, China.
² Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084 Beijing, China. Electronic address: xlyu@cugb.edu.cn.

PMID: 36067599
DOI: 10.1016/j.jcis.2022.08.120

Abstract

Photocatalytic CO₂ reduction is a promising method to resolve the energy shortage problem. Developing photocatalysts with strong redox capabilities is urgently needed to achieve high photocatalytic activity. Herein, we synthesized TiO₂/CsPbBr₃ S-scheme heterojunctions with modulated internal electric field by facet engineering of TiO₂ to control charge transfer for improved photocatalytic activity. Density functional theory (DFT) calculation reveals that there is a wider Fermi level difference between TiO₂-(101) and CsPbBr₃ than that between TiO₂-(001) and CsPbBr₃, which will induce more obvious band bending. Subsequently, more efficient spatial separation will occur around the interface. Thus, TiO₂-(101)/CsPbBr₃ heterostructures effectively reduce CO₂ into CO with the selectivity of 90.2 % and reduction rate of 12.5 μmol h^-1, 15.6 and 5.6 times improvement than that of 101-TiO₂ and TiO₂-(001)/CsPbBr₃, respectively. This report proposes a feasible idea of employing facet engineering to take the advantage of S-scheme heterojunction.

Keywords: CO(2) photoreduction; CsPbBr(3); Facet-dependent; Internal electric field; S-scheme.