Fe2(MoO4)3 modified hematite with oxygen vacancies for high-efficient water oxidation

Abstract A Fe2(MoO4)3-incorporated hematite photoanode was fabricated and showed a significantly enhanced photocurrent density comparing with the pristine hematite. The Fe2O3/Fe2(MoO4)3 photoanode can be well coupled with hydrogen-treatment to gain an enhanced photocurrent density of 2.47 mA cm−2 at 1.23 vs RHE with an obvious cathodic shift (~100 mV) of the onset potential. By loading with the FeNiOOH cocatalyst, the photoanode can yield an excellent photocurrent up to 3.08 mA cm−2 at 1.23 V vs RHE, which is comparable to the best performance for hematite-based photoanodes reported in the literatures. Data reveals that Fe2(MoO4)3 has been incorporated in hematite to boost the charge separation, and can be further modified by hydrogen-treatment to produce more oxygen vacancies due to the high valence state of Mo6+. The synergistic effect of the Fe and Mo sites with oxygen vacancies can obviously increase the charge transport and promote the charge separation, which will lead to an excellent PEC performance.