Hierarchically interconnected g-C₃N₄/BiVO₄/ZnO array via spin coating for high photoelectrochemical performance

An interconnected g-C₃N₄/BiVO₄/ZnO array system was constructed to enhance photoelectrochemical (PEC) performance. This study confirmed that an optimally decorated ZnO layer improves PEC performance by maximizing light absorbance and reducing charge recombination. Moreover, the layer also plays a significant role in passivating the underneath g-C₃N₄/BiVO₄ components to increase the stability of the photoanodes and charge carrier concentration. With the Z-scheme g-C₃N₄/BiVO₄ heterojunction structure, electrons can be easily transferred while blocking holes to minimize charge recombination. The oxygen vacancies in the ZnO layer are good for high PEC performance with a reduced bandgap of the g-C₃N₄/BiVO₄/ZnO array. The formation of interconnected interfaces reduces the interface contact resistance, promotes charge transfer, and consequently improves the PEC performance. The interconnected g-C₃N₄/BiVO₄/ZnO array is a promising candidate for overcoming the inherent negative properties of individual metal oxides for application in future solar-driven reaction systems.