Carbon Nanotube/ZnIn₂S₄ Nanocomposites with Efficient Spatial Charge Separation and Migration for Solar H₂ Generation

The addition of carbon materials to semiconductor catalyst systems can boost the activity of photocatalytic H2 production substantially. Herein, we prepared a series of carbon nanotube/ZnIn2S4 (CNT/ZIS) composites with different contents of CNTs through a simple hydrothermal process and investigated the effect of CNTs on hydrogen evolution performance of ZIS in detail. The electron–hole behavior of CNT/ZIS is studied by photocurrent density, linear sweep voltammetry, steady state, and transient fluorescence spectra. Meanwhile, its optical properties have been studied. Comprehensive experimental characterization and theoretical research reveal that CNTs can not only enhance the visible-light absorption property of composite materials but also efficiently separate the photoinduced carriers and supply more active sites. In consequence, CNT/ZIS exhibits superior photocatalytic H2 evolution. The optimal sample has a hydrogen production rate of 8904.2 μmol·g–1·h–1 under visible-light irradiation, which is 13.2 times higher than that of bare ZIS. Our work offers a simple, cheap, and green method for improving the photocatalytic performance of photocatalysts toward practical applications.