Developing a system for the production of organic chemicals via CO2 reduction is an important area of research that has the potential to address global warming and fossil fuel consumption. In addition, CO2 reduction promotes carbon source recycling. Solar energy is the largest exploitable resource among renewable energy resources, providing more energy to Earth per hour than the total energy consumed by humans in 1 year. This report describes the advantages and disadvantages of the available CO2 reduction and H2O oxidation photocatalysts and the conjugation of photocatalytic CO2 reduction with H2O oxidation for the creation of an artificial photosynthesis system. In this system, CO2 photoreduction and H2O photooxidation proceeded simultaneously within one system under sunlight irradiation using a hybrid of semiconductors and molecular metal-complex catalysts.