Graphitic carbon nitride for photocatalytic CO2 reduction

Among the various emerging photocatalytic materials, graphitic carbon nitride (g-C 3 N 4 ) has gained significant importance due to their two-dimensional (2D) structure, promising electronic, optical, and interfacial properties. The features such as narrow band gap energy, reduced recombination process, enhanced transportation of charge carriers to the surrounding, and appropriate band edge potential to produce the required redox species are making the g-C 3 N 4 as a promising candidate for various photocatalytic applications, especially for CO 2 reduction into hydrocarbon fuels. It should be noted that the CO 2 conversion essentially involves two simultaneous process known as the CO 2 reduction and protonation. The effectiveness in such simultaneous process requires the appropriate positioning of band edge potential in the system, which can be effectively engineered in g-C 3 N 4 -based materials as compared to the other metal oxide-based systems. Interestingly, in addition to the chemical induced redox process, the CO 2 conversion properties of g-C 3 N 4 can also be attributed to their physical structures such as 2D layers and porous structures, where it causes the shifting of band edge positions and enhanced CO 2 adsorption in g-C 3 N 4 . To this end, this chapter provides a glimpse of structure-property relationship of g-C 3 N 4 based materials towards their photocatalytic CO 2 conversion properties, where it discusses the various g-C 3 N 4 material systems and their efficiency towards the conversion of CO 2 into various hydrocarbon fuels under light visible light/sunlight irradiations.