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

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.