Pt Co-catalyst nanolayer on nanostructured V-doped Fe2O3 for boosting photoelectrochemical water oxidation

A defective system of V-doped Fe₂O₃ with Pt as a cocatalyst was employed for photoelectrochemical (PEC) water oxidation. The contained defects in VFPt-2.5 photoanode were revealed by XPS and EPR analyses. Interestingly, the morphology of electrodeposited V-doped α-Fe₂O₃ is observed to be nanosized with an average diameter size of ∼12 nm and thickness of 300 nm by SEM and TEM analyses. Under light irradiation, VFPt-2.5 photoanode achieved a remarkable onset potential of 0.22 V_RHE and a photocurrent density of 2.5 mA/cm² with an applied external bias at 1.23 V_RHE in 1 M KOH electrolyte solution (pH = 14). The calculated IPCE and ABPE values of VFPt-2.5 were ∼37% and 0.85%, respectively. The generated oxygen and hydrogen by VFPt-2.5//Pt were found to be 82 and 170 μmol. The stability of VFPt-2.5 reached 95.2% revealing that Pt could help to overcome the reversed effect of surface states that cause the charge recombination.