Local surface plasma resonance effect enhanced Z-scheme ZnO/Au/g-C3N4 film photocatalyst for reduction of CO2 to CO

Local Surface Plasma Resonance (LSPR) effect enhanced Z-scheme ZnO/Au/g-C3N4 micro-needles film (3-ZAC) has been prepared for the photoreduction of CO2 into CO under UV–vis light irradiation. Photoreduction experiments show that 3-ZAC has the excellent photocatalytic performance and reusability. The CO production can be achieved 689.7 μmol/m2 after 8 h reaction time, which is 4.5 higher than that of the pure ZnO film. 13C isotope test shows that CO is produced from CO2 by photoreduction. DFT calculations confirm that build-in electric field formed at g-C3N4/ZnO interface effectively promoted the electron transfer efficiency in Z-scheme interface. FDTD simulations prove that Au NPs not only act as electron-transfer bridge, but also as LSPR excited source to speed up the separation of electron-hole pairs. In-situ FTIR technique was used to investigate the CO2 photoreduction process. The above characteristics together maximize the electron transfer efficiency, which causes the material has enhanced photocatalytic performance.