Hydrogen generation from direct Z-scheme for photocatalytic overall water splitting with the SiSe/SnSe2 and SiSe/SnSSe heterostructures

• Published in: Journal of catalysis Vol. 432; p. 115429
• Main Authors: Wang, Fei, Yang, Chuan-Lu, Li, Xiao-Hu, Liu, Yu-Liang, Zhao, Wen-Kai
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2024
• Subjects: Direct Z-scheme; Gibbs free energy; Hydrogen evolution reaction; Nonadiabatic molecular dynamics simulation; Photocatalytic; Solar-to-hydrogen; Photocatalytic; Hydrogen evolution reaction; Gibbs free energy; Nonadiabatic molecular dynamics simulation; Solar-to-hydrogen; Direct Z-scheme
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2024.115429

[Display omitted] •Photocatalytic Z-schemes are built for SiSe/SnSe2 and SiSe/SnSSe heterostructures.•The STH efficiencies of the Z-schemes can reach 19.18%, 14.61%, and 14.24%.•NAMD simulations confirm photocatalytic activity of SiSe/SnSe2 is well-protected.•ΔGs reveal both HER and OER with SiSe/SnSSe-I can spontaneously proceed. The direct Z-schemes of the photocatalytic overall water splitting with the SiSe/SnSe2, SiSe/SnSSe-I, and SiSe/SnSSe-II heterostructures are constructed based on the density functional theory calculations and nonadiabatic molecular dynamics (NAMD) simulations. The maximum solar-to-hydrogen efficiency (ηʹSTH) reaches 19.18% and can be promoted to 28.71% under tensile biaxial strains. NAMD simulations indicate the transfer of the electron for hydrogen evolution reaction (HER) and hole for oxygen evolution reaction (OER) for SiSe/SnSe2 are apparently slower than those for the other two heterostructures, implicating the reduction and oxidation activities of this heterostructure are well-protected. Moreover, the shortest electron-hole recombination time is attributed to SiSe/SnSSe-I, indicating that it holds the best photocatalytic performance. Remarkably, the Gibbs free energies indicate that HER and OER with SiSe/SnSSe-I can spontaneously proceed, while OERs can but HERs cannot spontaneously proceed with the other two heterostructures. Therefore, the newfound heterostructures, especially SiSe/SnSSe-I, are promising candidates in photocatalytic overall water splitting.