Converting solar energy into fuel via photo-assisted water splitting to generate H2 or drive CO2 photoreduction is an attractive scientific and technological goal to address the increasing global demand for energy and to reduce the impact of energy production on climate change. Solar-driven hydrogenation of CO2 into value-added chemical products is one of the most promising strategies for reducing CO2 and is anticipated to be a sustainable energy source shortly. In this study, we focus on the utilization of different sustainable H2 sources for the photoreduction of CO2 to value-added organic products. Various photocatalysts, photoreactor configurations, and reaction parameters for the photoreduction of CO2 are discussed. For future research endeavors, a general approach for the photoreduction of CO2 to mimic natural photosynthesis, in which the H2 source is provided directly during the photocatalytic water splitting, is proposed and verified to generate value-added organic products successfully.
