Phosphorous-Doped High-Entropy Oxides Enabling Full Spectrum Utilization of BiVO₄ Photoanodes for Efficient Water Oxidation

High-performance BiVO₄ photoanodes generally requires elaborate modification on both bulk and surfaces, which inevitably increases the complexity of photoanode design. Herein, a phosphorus-doped high-entropy oxide composite (P-HEO) is decorated on a BiVO₄ photoanode (denoted as PHBVO), which achieves broadband solar absorption (86% in 300–2500 nm vs 31% for pristine BiVO₄) and delivers a photocurrent density of 6.36 mA cm⁻² at 1.23 V_RHE, representing a fourfold enhancement compared to pristine BiVO₄ photoanodes. Systematical studies reveal that lattice distortion in P-HEOs induces band structure reconstruction and oxygen vacancy formation, while interfacial P─O coupling promotes d-p orbital hybridization, reducing the oxygen evolution reaction overpotential. Moreover, the photothermal effect of P-HEOs suppresses carrier recombination, enhancing electron mobility by 2.6-fold. PHBVO demonstrates stability exceeding 160 h under continuous AM 1.5 G illumination, which is attributed to a robust high-entropy oxide interface. This work provides a proof-of-concept for the design of efficient photoanodes through surface modification simultaneously achieving the enhancement in light harvesting, carrier transport and surface catalytic activity.