The significant recombination of carriers and low OER kinetics depress the solar to chemical energy conversion efficiency over BiVO4. The introduction of a heterostructure or co-catalyst can solve the above limitations, but it is still challenging to further understand the interaction between the heterostructure and co-catalyst in an integrated system. In this work, for the first time, we developed a strategy for the confined growth of a Co–Pi co-catalyst via bonding coordination from a polydopamine (PDA) matrix, endowing the Co–Pi co-catalyst with desirable bond anchoring and dispersion on the surface of BiVO4 (Co–Pi/PDA/BiVO4). The photocurrent density of the 0.15-Co–Pi/PDA/BiVO4 heterostructure reached up to 2.47 mA cm−2 (1.23 V vs. RHE), which is about 7 times that of bare BiVO4. The optimal charge injection efficiency increased from 25% to 75% (1.23 V vs. RHE), and an IPCE value of 27% (400 nm, 1.23 V vs. RHE) was achieved. Due to the proposed mechanism, the organic–inorganic synergistic model contributed to the enhancement in photoelectrochemical performance.
