Dynamic Interfacial Polarization and Adaptive Electronic Modulation of Atomically Dispersed Pt Sites for Stable Solar Water Oxidation

Abstract

Bismuth vanadate (BiVO4) photoanodes suffer from sluggish oxygen evolution kinetics and severe charge recombination. Although Ni-based cocatalysts are widely used, low conductivity and insufficient active-site density remain bottlenecks. Herein, atomically dispersed Pt sites are constructed in NiOx-modified BiVO4 to enable light-driven dynamic interfacial polarization and adaptive electronic modulation for photoelectrochemical (PEC) water splitting. Mechanistic investigations based on in situ spectroscopies suggest that atomically dispersed Pt sites efficiently mediate photogenerated holes. Transient electron-deficient states in the valence orbitals drive rapid charge separation, while continuous electron compensation preserves a stable electron-shielded core for optimal catalytic turnover. Density functional theory (DFT) calculations further show that electronic metal-support interaction (EMSI) redistributes the free energy landscape across all proton-coupled electron transfer (PCET) steps, shifting the potential-determining step (PDS) from *OH to *OOH formation and mitigating linear scaling constraints. The optimized photoanode yields 6.30 mA/cm2 at 1.23 V vs the reversible hydrogen electrode (RHE), with charge injection/separation efficiencies of 96.2%/86.9% and a near-ideal 95% Faradaic efficiency (FE). This work offers a robust electronic regulation strategy for high-performance PEC water splitting.