Enhancing the PEC water splitting performance of In2O3 nanorods by a wet chemical reduction

Generating oxygen vacancies is an effective way to improve photoelectrochemical (PEC) water splitting performance of semiconductor materials owing to the formation of shallow donor level and the supply of additional electron donor. Herein, oxygen vacancies were introduced into In2O3 nanorods by a hydrothermal reduction method using NaBH4 solution as the reductant, and the effects of hydrothermal reduction time on the oxygen vacancy concentration, optoelectronic property and PEC water splitting activity over In2O3 nanorods were systematically investigated. The results of LSV, EIS and MS showed that the reduced samples displayed superior PEC performance and In2O3-x-1 exhibited a highest photocurrent density of 0.97 mA cm−2 at 1.23 V vs. RHE under the irradiation of visible light, which was roughly 4 times of bare In2O3. The remarkable performance of In2O3-x-1 is mainly ascribed to the introduction of oxygen vacancies, which leads to better light absorption capacity, higher carrier concentration, and increased electron transport efficiency at the electrode/electrolyte interface.