Fabrication of hierarchical ZnIn2S4@CNO nanosheets for photocatalytic hydrogen production and CO2 photoreduction

Abstract

Photocatalytic H2 production and CO2 reduction have attracted considerable attention for clean energy development. In this work, we designed an efficient photocatalyst by integrating lamellar oxygen-doped carbon nitride (CNO) nanosheets into ZnIn2S4 (ZIS) microflowers by a one-step hydrothermal method. A well-fitted 2D hierarchical hybrid heterostructure was fabricated. Under visible light irradiation, the ZIS@CNO composite with 40 wt% CNO (ZC 40%) showed the highest hydrogen evolution rate from water (188.4 μmol·h−1), which was approximately 2.1 times higher than those of CNO and ZIS (88.6 and 90.2 μmol·h−1, respectively). Furthermore, the selective CO production rates of ZC 40% (12.69 μmol·h−1) were 2.2 and 14.0 times higher than those of ZIS (5.85 μmol·h−1) and CNO (0.91 μmol·h−1), respectively, and the CH4 production rate of ZC 40% was 1.18 μmol·h−1. This enhanced photocatalytic activity of CNO@ZIS is due mainly to the formation of a heterostructure that can promote the transfer of photoinduced electrons and holes between CNO and ZIS, thereby efficiently avoiding recombination of electron-hole pairs.