Phosphorous‐Doped High‐Entropy Oxides Enabling Full Spectrum Utilization of BiVO ₄ Photoanodes for Efficient Water Oxidation

Abstract High‐performance BiVO ₄ 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 BiVO ₄ photoanode (denoted as PHBVO), which achieves broadband solar absorption (86% in 300–2500 nm vs 31% for pristine BiVO ₄ ) and delivers a photocurrent density of 6.36 mA cm ⁻² at 1.23 V _RHE , representing a fourfold enhancement compared to pristine BiVO ₄ 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.