Addressing the inherent holes transport limitation of BiVO4 photoanode is crucial to achieve efficient photoelectrochemical (PEC) water splitting. The construction of the hole-transfer bridge between co-catalysts and BiVO4 photoanode could be an effective way to overcome sluggish hole-transfer kinetics of BiVO4 photoanode. Herein, CxNy/BiVO4 photoanode was prepared by coupling carbon nitride hydrogel (CNH) containing unsaturated N on the BiVO4 photoanode during annealing. CxNy/BiVO4 photoanode exhibited excellent PEC performance and stability. Photoelectrochemical tests proved that the coupling of CxNy accelerated holes transfer and enhanced oxygen evolution kinetics. X-ray photoelectron spectroscopy (XPS) and theoretical calculations confirmed the existence of the Bi-N-V bond between BiVO4 photoanode and CxNy, which could serve as the hole-transfer bridge to significantly accelerate separation and transfer of carriers driven by the interfacial electric field. Moreover, it was found that the coupling of CxNy effectively inhibited the dissociation of metal ions through changing their coordination environment, resulting in the excellent stability of CxNy/BiVO4 photoanode. This result provides unique insights into vital roles of the interfacial structure, which might have a significant impact on the construction of PEC devices. (C) 2021 Elsevier Inc. All rights reserved.