Self-assembled electron-rich interface in defected ZnO:rGO-Cu:Cu2O, and effective visible light-induced carbon dioxide photoreduction

[Display omitted] •Design of defected-ZnO:rGO-Cu:Cu2O photocatalyst.•Self-assembled electron-rich interface and lattice oxygen defect.•Efficient charge separation and enhanced light harvesting. As an ecological mimicry system, carbon dioxide (CO2)-to-fuel conversion in artificial photosynthesis is quite attractive as a method to simultaneously solve the global energy crisis and environmental problems. Although many researchers have spent a lot of time on efficient charge separation and on enhanced light harvesting, photocatalysts still exhibit poor activity. Nevertheless, designing new types of photocatalysts is still worth attempting. Herein, a localized surface plasmon resonance enhanced the self-assembled rGO-Cu electron-rich interface in a defected ZnO:rGO-Cu:Cu2O composite resulted to inhibit the relaxation of excited electrons by continuously supplying electrons into the vacant holes of Cu2O. The defected ZnO exhibited a diminished band-gap and a higher adsorption of CO2. Under visible irradiation, methane (CH4) produced from CO2 accumulated to 41.0 μ mol g−1 over 10 h on def-ZnO:rGO-Cu:Cu2O, which corresponded to at least 10 times the CH4 amounts compared with the reported ZnO-based catalysts. Ultimately, this work provided new approaches for designing photocatalysts to improve CO2 conversion in gas-phase reaction systems as self-assembling the electron-rich interface and inducing the lattice oxygen defect.