Fabrication and performance of a 3D porous graphene aerogel-supported Ni–ZnS composite photocatalyst

The performance of a Ni–ZnS/three-dimensional (3D) graphene aerogel (GA) composite photocatalyst for hydrogen production was investigated in this study. Ni–ZnS precursor was loaded on 3D graphene aerogel through a simple solvothermal method, and the composite Ni–ZnS/GA was successfully synthesized. The average hydrogen production rate of Ni–ZnS/GA-4 can reached 12.06 mmol·g⁻¹·h⁻¹ and after three cycles for 9 h, the hydrogen production efficiency remained at 97.81%. Ni²⁺ doping provided suitable band gap for ZnS, which could fully absorb sunlight, and made the photo-generated carriers have sufficient redox ability. The large specific surface of 3D graphene gel enhanced the dispersion of nano Ni-ZnS, boosted photo-generated carrier separation, and accelerated sacrificial agent adsorption. The Ni–ZnS/GA composite had more active adsorption sites and photocatalytic reaction centers, improving photocatalytic activity and efficiency.