TiO2 has been well studied as an ultraviolet (UV) photocatalyst and electrode material for lithium-ion rechargeable batteries. Recent studies have shown that hydrogenated TiO2 displayed better photocatalytic and lithium ion battery performances. Here it is demonstrated that the photocatalytic and battery performances of TiO2 nanocrystals can be successfully improved with a facile low-temperature vacuum process. These TiO2 nanocrystals extend their optical absorption far into the visible-light region, display nanometer-scale surface atomic rearrangement, possess superoxide ion characteristics at room temperature without light irradiation, show a 4-fold improvement in photocatalytic activity, and has 30% better performance in capacity and charge/discharge rates for lithium ion battery. This facile method could provide an alternative and effective approach to improve the performance of TiO2 and other materials towards their practical applications.