Boosted photoelectrochemical performance of In2O3 nanowires via modulating oxygen vacancies on crystal facets

Abstract

Introducing oxygen vacancies into faceted metal oxide nanostructures will largely boost photoelectrochemical water splitting ability, but currently remains a huge challenge. Herein, a simple one-step chemical vapor deposition method is developed to effectively introduce oxygen vacancies into In2O3 nanowires with the active {001} facets exposed. Theoretical calculations reveal that the introduction of oxygen vacancies produces a new defect level as shallow donor and increases the states of density, thereby enhancing the visible light absorption and promoting the separation and transportation of photogenerated carrier of faceted In2O3 nanowires. The In2O3 nanowires grown at optimal condition yield the maximal photocurrent density of 1 mA/cm2 at 0.22 V versus Ag/AgCl with unity Faradic efficiency. The results demonstrate that introducing oxygen vacancies into faceted photoelectrodes is feasible for further promoting the photoelectrochemical performance. Moreover, the methodology can be extended to other practical optoelectronic devices such as solar cell and photodetectors.