Expediting hole transfer kinetics through surface state modulation of a Ru–FeOOH and FeNi(OH)x dual-layer cocatalyst coated Zr–Fe2O3 photoanode for boosting photoelectrochemical water splitting

Ru–FeOOH and FeNi(OH) x dual-layer cocatalysts passivated the recombination surface states, resulting in the Fermi level de-pinning effect, while tailoring the intermediate surface states for effective hole transfer to the electrolyte.