Efficient synthesis of tunable band-gap CuInZnS decorated g-C3N4 hybrids for enhanced CO2 photocatalytic reduction and near-infrared-triggered photodegradation performance

By rationally adjusting the band position of CuInZnS in CuInZnS/g-C3N4 hybrids, we reveal the effects of fine turning the band matching on CO2 reduction and methyl orange near-infrared degradation. The novel design strategy of CuInZnS/g-C3N4 hybrids, including orderly energy band regulation of CuInZnS and surface carboxylation of g-C3N4, effectively enhances the light absorption capacity and separation efficiency of photogenerated carriers. In addition, L-cysteine was used as sulfur source for in situ synthesis of hybrids. Using the abundant functional groups of L-cysteine molecules to form bonds and interactions with carboxylated g-C3N4 can effectively improve the dispersion and interface binding of CuInZnS/g-C3N4 hybrids, thus enhancing the transport of carriers at the interface. Benefitting from band matching and interface binding characteristics, the optimized CuInZnS/g-C3N4 hybrids manifest remarkable performance for CO2 reduction with high CO production rate of 50.04 mu mol/g in 8 h and excellent activity for methyl orange near-infrared degradation with 96.5% efficiency in 5 h.