Facile and Universal Strategy to Construct Piezo-Photocatalytic Systems via Building Electron Bridges for Highly Efficient Overall Water Splitting

The integration of piezoelectric and photocatalytic materials to enhance the separation of photogenerated charge carriers for overall water splitting (OWS) gives prospects for the application of solar-to-chemical energy conversion. However, high interfacial resistance and poor charge transport remain challenges for the construction of piezo-photocatalytic systems. In this study, we applied the piezoelectric effect to photocatalysts in a simple and universal manner through building electron bridges, achieving an apparent quantum efficiency of 4.4% at a wavelength of 420 ± 20 nm. The conducting polymer polyaniline (PANI), for the first time, was used to bridge the piezoelectric material ZnO and the photocatalyst (ZnO)_1-<i>x</i>(GaN)<i>_<i>x</i></i> by in situ polymerization, which served as an electron bridge to transfer the piezoelectric effect. This work offers new possibilities for realizing efficient charge transfer and separation as well as universal applicability of building electron bridges between piezoelectric materials and photocatalysts for efficient OWS.