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

•Cu nanoparticles modified TiO2 nano-flower film was prepared by a facile strategy.•Cu nanoparticles can enhance the light absorption and the Raman scattering of TiO2.•Cu nanoparticles can effectively restrain the recombination of the charge carriers.•A synergistic mechanism is proposed for photocatalytic reduction of CO2 on Cu/TiO2 film.

Cu nanoparticles (NPs) deposited TiO2 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 TiO2 film both exhibit visible light harvesting properties based on localized surface plasmon resonance (LSPR) of Cu NPs and unique nanostructures of TiO2 film. Fluorescence quenching was observed because the recombination of charge carriers was effectively suppressed by Cu NPs deposition. The experimental results indicate that Cu/TiO2 films exhibit better activity for the photocatalytic reduction of CO2 due to the charge transfer property and LSPR effect of Cu NPs. The CH3OH production rate reached 1.8 μmol cm−2 h−1 (energy efficiency was 0.8%) over 0.5 Cu/TiO2 film under UV and visible light irradiation, which was 6.0 times higher than that observed over pure TiO2 film. In addition, a tentative photocatalytic mechanism is proposed to understand the experimental results over the Cu modified TiO2 nano-flower films.

Graphical abstractPhotoreduction of CO2 to CH3OH over plasmonic Cu/TiO2 film.Figure optionsDownload full-size imageDownload as PowerPoint slide