Photo-driven seawater splitting is considered as one of the most promising techniques for sustainable hydrogen production. However, the high salinity of seawater would deactivate catalysts and consumes the photogenerated carriers. Metal vacancies in metal oxide semiconductors are critical to directed electron transfer and high salinity resistance, thus desirable but remains 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 photo-driven seawater splitting, including photocatalysis and photoelectrocatalysis. Experimental measurements and theoretical calculations reveal the formation of titanium vacancies, as well as its unidirectional electron trap and superior H + adsorption ability for efficient charge transfer and corrosion resistance of seawater. Therefore, the characteristics and mechanism have been proposed at an atomic-/nanoscale to clarify the generation of titanium vacancies and the corresponding interfacial electron transfer.