Fabrication of ZnMn2O4@ZnIn2S4 Ball-in-Ball Hollow Microspheres as an Efficient Photocatalyst for Hydrogen Evolution

Semiconductor photocatalytic hydrogen evolution (PHE) has emerged as a feasible solution to address the problem of energy shortage. Hydrogen energy can thus be developed by creating a photocatalyst with a high activity for producing hydrogen and an effective charge transfer route. This study describes the preparation of innovative hierarchical ZnMn2O4@ZnIn2S4 (ZMOZ) ball-in-ball hollow microspheres as photocatalysts using a straightforward solvothermal technique. Remarkably, the PHE rate of the 10% ZMOZ can reach 11.12 mmol h–1 g–1, it roughly 4.9 greater than pure ZnIn2S4 (ZIS). Aside from the benefits of building heterojunctions, the regulation of morphology such as hollow structures that can provide more exposed active sites and enhance the light-absorption capability by internal multilight scattering. Through the use of density functional theory calculations (DFT), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra as well as time-resolved PL (TRPL) spectroscopy also demonstrate that the charge separation efficiency in the composite was notably improved. This work offered a cost-effective and environmentally friendly method for utilizing visible light to construct an effective PHE.