Titanium Vacancies in TiO2 Nanofibers Enable Highly Efficient Photodriven Seawater Splitting

Abstract Photodriven seawater splitting is considered to be one of the most promising techniques for sustainable hydrogen production. However, the high salinity of seawater would deactivate catalysts and consume the photogenerated carriers. Metal vacancies in metal oxide semiconductors are critical to directed electron transfer and high salinity resistance; they are thus desirable but remain a challenge. We demonstrate a facile controllable calcination approach to synthesize TiO 2 nanofibers with rich Ti vacancies with excellent photo/electro performances and long‐time stability in photodriven seawater splitting, including photocatalysis and photo‐electrocatalysis. Experimental measurements and theoretical calculations reveal the formation of titanium vacancies, as well as unidirectional electron trap and superior H + adsorption ability for efficient charge transfer and resistance to corrosion by seawater. Therefore, atomic‐/nanoscale characteristics and mechanism have been proposed to clarify the generation of titanium vacancies and the corresponding interfacial electron transfer.