Photocatalytic conversion of CO2 to either a renewable fuel or valuable chemicals, using solar energy has attracted more and more attention, due to the great potential to provide an alternative clean fuel and solve the problems related to the global warming. This review covers the current progress of photocatalytic conversion of CO2 by photocatalysis over the metal oxides. A brief overview of the fundamental aspects for artificial photosynthesis has been given and the development of novel photocatalysts for CO2 photoreduction has been discussed. Several key factors for high-efficiency CO2 photoreduction and the recent development of photocatalytic reactor design for this artificial photosynthesis have also been highlighted. (C) 2014 The Authors. Published by Elsevier B.V. All rights reserved.