Heterojunction engineering decorated TiO2/ZnO three‐dimensional hierarchical structure with g‐C3N4 for solar driving water splitting

Abstract

AbstractImproving the carrier separation efficiency plays a decisive role in designing and constructing a high‐efficiency photocatalysis reaction system. Derived from providing a directional transport channel for photogenerated carriers, three‐dimensional (3D) nanostructures greatly improve the charge separation efficiency. Herein, TiO2/ZnO (TZ)/g‐C3N4 3D hierarchical nanostructure was constructed to artificially simulate photosynthesis of green plants. The optimal TZ/g‐C3N4 photoanode exhibits a photocurrent density of 1.46 mA/cm2 at 1.23 V versus reversible hydrogen electrode potential, 1.6 times that of pure TiO2 (0.9 mA/cm2). Moreover, under constant illumination (100 mW/cm2), the hydrogen production reached 80 μmol/cm2 within 180 min. It is worth noting that the TZ/g‐C3N4 photoanode shows surprising stability, which is an important indicator for the practical application of the photoelectrode. The excellent photoelectrochemical performance benefits from the following two aspects: TZ nanotree structure provides a directional transport channel for photogenerated carriers, and the modification of TZ by g‐C3N4 extends the response range to the visible region.