Regulating charge transfer over 3D Au/ZnO hybrid inverse opal toward efficiently photocatalytic degradation of bisphenol A and photoelectrochemical water splitting

Plasmonic photocatalytic degradation and photoelectrochemical water splitting is very promising in the process of ecological environment protection. However, the efficiencies reported are still too low for practical application due to the high recombination of photogenerated electrons and holes, which can be improved by optimizing the design and assembly of highly ordered pore structures. In our work, a composite plasmonic metal/semiconductor photocatalyst, Au/ZnO hybrid inverse-opal nanomaterial (Au/ZnO-IO), was prepared by in-situ grown Au nanoparticles on inner and outer of ZnO framework. The 3D ordered Au/ZnO-IO photocatalyst exhibited excellent photocatalytic activity in bisphenol A degradation and photoelectrochemical water splitting. The improved photoactivities were proved to be caused by the increased light absorption and special charge transfer of photogenerated electrons, which significantly restraint the recombination rate and prolong the lifetime of photoexcited carries. Based on the analysis of active species experiments, photoelectrochemical measurements, energy level of schottky junction and finite-difference time-domain (FDTD) simulations, the degradation mechanism on Au/ZnO-IO nanocomposite was supposed. This work provides insights into the charge transfer regulation by constructing the 3D plasmonic metal/semiconductor inverse-opal photocatalyst and may serve as a promising strategy for photocatalytic degradation of organic pollutants and water splitting.