Recent Progress in the Photocatalytic Reduction of Carbon Dioxide

Elimination or reduction of CO2 in the atmosphere is a serious problem faced by humankind, and it has become imperative for chemists to find ways of transforming undesirable CO2 to useful chemicals. One of the best means is the use of solar energy for the photochemical reduction of CO2. In spite of considerable efforts, discovery of stable photocatalysts which work in the absence of scavengers has remained a challenge although encouraging results have been obtained in the photocatalytic reduction of CO2 in both gas and liquid phases. Semiconductor-based catalysts, multicomponent semiconductors, metal–organic frameworks (MOFs), and dyes as well as composites involving novel composite materials containing C3N4 and MoS2 have been employed for the photoreduction process. Semiconductor heterostructures, especially those containing bimetallic alloys as well as chemical modification of oxides and other materials with aliovalent anion substitution (N3– and F– in place of O2–), remain worthwhile efforts. In this article, we provide a brief perspective of the present status of photocatalytic reduction of CO2 in both liquid and gas phases.