Dual-functional copper (Cu0/Cu2+)-modified SrTiO3-δd nanosheets with enhanced photothermal catalytic performance for CO2 reduction and H2 evolution

In recent years, metal-semiconductor heterojunctions have been intensively researched in the field of photocatalysis due to the effective spatial separation of photo-induced electron-hole pairs. Here, the dual-functional copper (Cu-0/Cu2+)-modified SrTiO3-delta nanosheets (Cu/STCO) are successfully synthesized by a two-step route. First, Cu2+-doped SrTiO3-delta (STCO) nanosheets are synthesized by a hydrothermal method and then Cu0 nanoparticles (NPs) are in situ formed from the STCO under H-2 atmosphere at 500. C. The optimized ratio 6 %-Cu/ STCO photocatalyst exhibits the best photothermal catalytic performance for CO2 reduction reaction (CO2RR) and H-2 evolution performance. The detailed characterization demonstrate that the Cu2+ dopant extend the light absorption range and the in situ generated Cu-0 NPs effectively improve the separation ability of photogenerated charge carriers by forming the Schottky contact with STCO. The excited localized surface plasmon resonance (LSPR) effect of metallic Cu-0 in Cu/STCO shows a considerable catalysis performance even under 600 nm monochromatic light irradiation. The density functional theory (DFT) calculations suggest that the Cu/STCO diminishes the barrier of the rate-determining steps of the CO2RR and H-2 evolution thus perform the outstanding catalysis ability in two filed. This work presents the synergistic effect of Cu-0 and Cu2+ on enhancing the photothermal catalytic performance for CO2RR and H-2 evolution and offers a novel strategy to synthesize the metal-semiconductor nanostructures for efficient harnessing of solar energy into fuel.