Facet-oriented h-WO 3 /BiVO 4 photoanodes coupled with fluorine-tuned MnOOH cocatalysts for enhanced photoelectrochemical water oxidation

. Electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and photoluminescence analyses further confirm reduced interfacial resistance, accelerated carrier transport, and suppressed recombination. Density functional theory calculations suggest that F incorporation redistributes charge around Mn sites and lowers the thermodynamic limitation of the *OH to *O step. This work demonstrates a rational strategy for coupling crystallographic scaffold engineering with cocatalyst electronic modulation to improve PEC water oxidation.