An overview on g-C3N4 as a robust photocatalyst towards the sustainable generation of H2 energy

Modern society currently depends upon fossil fuels as the prime energy source. Their vast demand has guided to a vital energy calamity as fossil fuels are insufficient and exhaustible. Renewable energy sources have emerged as potential alternatives. H2 gas is expected to meet upcoming energy challenges and address environmental hurdles successfully. Different techniques such as biological conversion, water electrolysis, wind-powered hydrogen production, coal and other hydrocarbons gasification, steam methane reforming and photocatalytic water splitting are being used for the production of hydrogen energy. Among these, the most promising and renewable approach is photocatalytic water splitting as it uses abundantly available water resources and solar energy. Graphitic carbon nitride (g-C3N4) is recognized as an efficient photocatalyst for the generation of hydrogen because of its proper band structure, low cost, easy synthesis, excellent thermal and chemical stability and visible light adsorption ability. In the present study, we have briefly discussed various synthesis strategies and structure of g-C3N4. The mechanism of photocatalytic hydrogen generation over g-C3N4 has been depicted. The challenges in this photocatalytic system for generation of H2 energy were highlighted and future perspectives have been presented to address these challenges.