Enhanced photocatalytic hydrogen activities of CoV-LDH/ZnIn2S4 nanocomposites

Abstract

In this work, CoV-LDH/ZnIn₂S₄ (CoV-LDH/ZIS) nanocomposites were synthesized through a self-assembly process in order to investigate the influence of CoV-LDH addition on the rate of hydrogen production. XRD and TEM measurements confirmed the effective preparation of CoV-LDH/ZIS nanocomposites. Among all the nanocomposite photocatalysts, 2.0%-CoV-LDH/ZIS showed the best photocatalytic performance with a hydrogen production rate of 1397.3 μmol g⁻¹ h⁻¹, approximately 2.2 times that of pure ZnIn₂S₄ (ZIS). The X-ray photoelectron spectroscopy (XPS) measurement indicated that there is a strong interfacial interaction between ZIS and CoV-LDH, indicating that more than simple mechanical mixing had occurred. The steady-state fluorescence spectroscopy (PL) and time-resolved photoluminescence (TRPL) spectroscopy results showed that the electron and hole recombination in CoV-LDH/ZIS is significantly reduced and that efficient interface charge transfer and separation are achieved. This work sheds light on the interfacial electron transfer between two semiconductor materials, which promotes the separation of photogenerated carriers and thus enhances photocatalytic hydrogen production activity.