Solar-driven CO2 photoreduction into fuels has great potential in addressing the environmental and energy crisis. Heterophase TiO2 has attracted increasing attention in photoenergy applications owing to its fascinating properties, but much more attention has been paid on photodegradation and photocatalytic water splitting than that of photocatalytic CO2 reduction. Herein, anatase-rutile heterophase TiO2 nanoparticles with oxygen vacancy (TiO2-x) were successfully synthesized by involving proper amounts of polyols (EG, DEG, TEG, etc.) into the reaction system. The heterophase TiO2-x nanoparticles could accelerate the electron-hole separation and exhibit superior photocatalytic activity for reducing CO2 into methane. This work offers an alternative approach to simply fabricate TiO2-x-based heterophase photocatalyst towards efficient CO2 photoreduction. (C) 2020 Elsevier Inc. All rights reserved.