Recent Developments in Graphitic Carbon Nitride and Its Interfaces for Effective Water Splitting

Electrocatalytic and photocatalytic water splitting are effective pathways for energy conversion to overcome from the reliance on the depletion fossil fuels and preclude the severe degradation of global climate. The review begins with the basic principle and mechanisms involved in both electro/photocatalysis of water splitting. Graphitic carbon nitride (g‐C 3 N 4 ) is an interesting catalyst for water splitting due to its layered conjugated metal free semiconductor, owing to its unique physicochemical characteristics. However to improve some of the features of g‐C 3 N 4 including long term stability, large active sites, electronic band structure, low recombination rate of photogenerated charges, and many more, interface engineering with different materials have been introduced to improve the catalytic activity. The review emphasizes the basics of g‐C 3 N 4 with its interesting properties such as chemical and thermal stability, large surface area, unique optoelectronic properties, exfoliated layered structure, and tunable surface functional groups. The various strategies that have been used to modulate catalytic activity of this material are discussed, including morphology modulation, elemental doping, interface engineering with metals, and semiconductors. Towards end of the review, a summary and future perspective is presented.