The synthesis and key features of 3D carbon nitrides (C3N4) used for CO2 photoreduction

CO2 concentration in the atmosphere has reached an all-time high, leading to global warming. The scientific community has suggested photocatalytic CO2 reduction as a reliable method to reduce CO2 concentration and produce clean energy. Carbon nitride-based photocatalysts have caught community attention due to their activity in visible light, easy and inexpensive synthesis, and higher reduction potential than required for CO2. Morphology engineering is one of the ways to enhance photocatalytic properties, as 3D carbon nitrides (C3N4) have larger surface areas, higher light harvesting ability, and slower charge carrier recombination than the bulk form. This review article summarizes the synthesis and characteristics of 3D C3N4-based photocatalysts reported for CO2 photoreduction. 3D C3N4-based photocatalysts have executed an excellent performance in the field of CO2 photoreduction. This review will aid in understanding the use of 3D C3N4 in CO2 photoreduction, the related present studies, and research gaps that will be of service in future research.