A facile strategy to fabricate plasmonic Cu modified TiO2 nano-flower films for photocatalytic reduction of CO2 to methanol

Abstract Cu nanoparticles (NPs) deposited TiO 2 nano-flower films were fabricated using a combination of a hydrothermal method and a microwave-assisted reduction process. The investigations indicated that Cu NPs and TiO 2 film both exhibit visible light harvesting properties based on localized surface plasmon resonance (LSPR) of Cu NPs and unique nanostructures of TiO 2 film. Fluorescence quenching was observed because the recombination of charge carriers was effectively suppressed by Cu NPs deposition. The experimental results indicate that Cu/TiO 2 films exhibit better activity for the photocatalytic reduction of CO 2 due to the charge transfer property and LSPR effect of Cu NPs. The CH 3 OH production rate reached 1.8 μmol cm −2  h −1 (energy efficiency was 0.8%) over 0.5 Cu/TiO 2 film under UV and visible light irradiation, which was 6.0 times higher than that observed over pure TiO 2 film. In addition, a tentative photocatalytic mechanism is proposed to understand the experimental results over the Cu modified TiO 2 nano-flower films.