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

[Display omitted] •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.•Au NPs at the interface of ZnO/g-C3N4 not only act as the electron-transfer bridge, but also as LSPR excited source to speed up the separation of electron-hole pairs photogenerated in the semiconductors.•DFT calculation and FDTD simulation methods has been used to prove the transfer processes of photogenerated electron. The photoproduction of CO from the photocatalytic CO2 reduction process has been evidenced from 13C isotope tracer tests.•This work demonstrates the importance of the build-in electric field formed at g-C3N4/ZnO interface and local electromagnetic field of Au NPs for the photoreduction process, providing an inspiring concept for future advancement in this area. 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.