Design of a noble-metal-free direct Z-scheme photocatalyst for overall water splitting based on a SnC/SnSSe van der Waals heterostructure. Issue 38 (28th September 2021)

• Record Type: Journal Article
• Authors: Jiang, Xinxin; Gao, Quan; Xu, Xuhui; Xu, Ge; Li, Dongmei; Cui, Bin; Liu, Desheng; Qu, Fanyao
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 38(2021)
• Page Start: 21641
• Page End: 21651
• Publication Date: 2021-09-28
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp03398k
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We propose a noble-metal-free direct Z-scheme photocatalyst for overall water splitting based on a Janus vdWH composed of SnC and Janus SnSSe monolayers with an STH efficiency of up to 60.8%. Abstract : Semiconductor photocatalysts, using sunlight to stimulate various photocatalytic reactions, are promising materials for solving the energy crisis and environmental problems. However, the low photocatalytic efficiency and high cost pose major challenges for their widespread application. Mimicking the natural photosynthesis system, we propose a direct Z-scheme photocatalyst based on a Janus van der Waals heterostructure (vdWH) comprising SnC and Janus SeSnS monolayers. From first-principles calculations, the intrinsic built-in electric field of Janus SeSnS and the charge transfer from the SnC to the SeSnS layer give rise to a type-II band alignment. Such a band alignment benefits the formation of spatially separated reductive and oxidative active sites and the reduction of the global bandgap of the Janus vdWH. The proposed material increases the solar-to-hydrogen conversion efficiency to 60.8%. Besides, we also find that the light absorption coefficient is stacking configuration controllable and strain-tunable, e.g., the tensile strain promotes photocatalytic efficiency. Moreover, because Sn, S, and Se are environmentally benign and inexpensive elements, SnC/SeSnS vdWH is a promising noble-metal-free direct Z-scheme photocatalyst.