Sulfonated graphene oxide-doped zincoxysulfide composites with enhanced photocatalytic hydrogen production performance

Abstract

Sulfonic acid groups were introduced onto graphene oxide (GO) via sulfonation reaction to prepare sulfonated graphene oxide (SG). Then, zincoxysulfide–SG composite photocatalysts were prepared by mixing SG and zincoxysulfide (ZnS1−xOx) nanoparticles. The morphology, crystalline properties, bandgap, and photocatalytic H2 production activity of these photocatalysts were investigated by FESEM, XRD, Mott–Schottky plots, and H2 production tests. The photocatalytic H2 production rates of Ce-doped zincoxysulfide–SG photocatalyst under UV and visible light irradiation reach 2100 and 700 μmol g−1 h−1, respectively. The improved H2 evolution activity of Ce-doped zincoxysulfide–SG composite photocatalysts can be attributed to the strong interaction between SG sheets and zincoxysulfide nanoparticles. By introducing sulfonated graphene oxide and Ce-doping, SG–zincoxysulfide photocatalysts exhibit stable and high photocatalytic H2 production activity, resulting from increased specific surface area, efficient charge separation, decreased bandgap and enhanced light absorption. After 3 cycles, the photocatalytic activity of recycled C2ZG2 photocatalyst remains at about 93.8% of its original activity.