Surface Cu+ modified ZnIn2S4 for promoted visible-light photocatalytic hydrogen evolution

• Published in: Journal of energy chemistry 2022-11, Vol.74, p.341-348
• Main Authors: Jia, Wen Li, Li, Wen Jing, Yuan, Hai Yang, Wu, Xuefeng, Liu, Yuanwei, Dai, Sheng, Cheng, Qilin, Liu, Peng Fei, Yang, Hua Gui
• Format: Article
• Language: English
• Subjects: Charge separation and transportation; HOMO-LUMO spatial separation; Photocatalytic hydrogen evolution; Surface modification; Univalent copper species
• ISSN: 2095-4956
• DOI: 10.1016/j.jechem.2022.07.022

Surface Cu+ modified ZnIn2S4 photocatalysts with spatial separation of energy levels remarkably suppress the recombination of electron and hole and thus enhance the photocatalytic H2 evolution. [Display omitted] Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation. Here, univalent copper species were modified on ZnIn2S4 photocatalyst via an in-situ photodeposition method, exhibiting a much higher H2 evolution rate of 41.10 ± 3.43 mmol g−1 h−1 and an impressive apparent quantum efficiency (AQE) of 20.81% at 420 ± 15 nm. Our characterizations indicate that the surface modification by copper species can broaden light utilization as well as promote charge separation and transportation. Besides, the density functional theory (DFT) results further exhibit that the energy levels (LUMO and HOMO) for copper-surface modified ZnIn2S4 present spatial separation, locating on the Zn-S and In-S layers, respectively, which can suppress the recombination of electron and hole and thus achieves higher photocatalytic H2 evolution efficiency.