Copper vanadate (Cu₃V₂O₈) has emerged as a promising material for photoelectrochemical applications due to its unique electronic and optical properties. In this study, the preparation of Cu₃V₂O₈ photoelectrodes with different thicknesses was reported and the factors that affect their photoelectrochemical performance were investigated. It is found that the primary limitation of Cu₃V₂O₈ as a photoanode material is the short diffusion distance of the photo-generated charge carriers, which leads to severe bulk recombination and limits the photocurrent density and efficiency. To overcome this limitation, a novel strategy of using one-dimensional ZnO nanorod arrays as a support framework and loading CoPi cocatalyst to enhance the photoelectrochemical performance of Cu₃V₂O₈ was proposed. The ZnO nanorod arrays serve as a rapid electron transfer channel to promote the bulk separation of photo-generated charge carriers, while the CoPi cocatalyst improves the surface separation efficiency of photo-generated charge carriers and enhances the oxidation kinetics. The incorporation of ZnO nanorod arrays and CoPi cocatalyst significantly enhances the photocurrent density and efficiency of Cu₃V₂O₈ photoelectrodes, resulting in a more than 2-fold increase in the photocurrent density and a 50% increase in the photoconversion efficiency. To further understand the underlying mechanisms behind the improved photoelectrochemical performance, a comprehensive analysis of the intensity-modulated photocurrent spectroscopy and electrochemical impedance spectroscopy data was performed. The results show that the incorporation of ZnO nanorod arrays and CoPi cocatalyst leads to a significant reduction in the charge transfer resistance and a decrease in the recombination rate of photo-generated charge carriers, which are responsible for the improved photocurrent density and efficiency. Overall, the study demonstrates the potential of using ZnO nanorod arrays and CoPi cocatalyst as a novel strategy to enhance the photoelectrochemical performance of Cu₃V₂O₈ photoelectrodes. The proposed approach provides a new direction for the development of high-performance photoanode materials for solar energy conversion and other photoelectrochemical applications.