A novel strategy for surface treatment on hematite photoanode for efficient water oxidation

Abstract

In this paper, we report a novel strategy for surface treatment of hematite nanorods for efficient photo-driven water oxidation. This is the first report describing the growth of Sn treated hematite from α-FeOOH nanorod arrays in one step without substantially altering morphologies. With this treatment the photocurrent density increased from 1.24 for pristine hematite nanorods to 2.25 mA cm⁻² at 1.23 V vs. RHE (i.e. 81% improvement). The increase in photocurrent density was also accompanied by improved incident-photon-to-current efficiencies and oxygen evolution. The photocurrent improvement is mainly attributed to a reduced electron–hole recombination at the hematite–electrolyte interface through the formation of Fe_xSn_1−xO₄ layer at the hematite nanorod surface as shown by XPS, HRTEM, EDAX line scan analyses and PEC measurements.