Recent progress in carbon nitride photocatalysts: Challenges, opportunities and future

For a wide range of photocatalytic uses, graphitic carbon nitride's (g-C3N4) exceptional physicochemical, optical, and structural characteristics have made it an attractive metal-free semiconductor candidate. Highlighting tactics such as heterojunction construction, morphology control, heteroatom doping, and defect engineering to improve photocatalytic efficiency, this review offers a thorough synopsis of current developments in the synthesis, modification, and functionalization of g-C3N4-based materials. We assess their efficacy in a variety of contexts, including water splitting, carbon dioxide reduction, degradation of pollutants, antibiotic activity, and sensing. We go over the correlations between structural features, photocatalytic performance, and synthesis factors in detail, as well as the present constraints, such as charge-carrier recombination, limited visible-light absorption, and stability issues. Emphasizing the potential of g-C3N4 in sustainable energy production and environmental remediation, we conclude by outlining new opportunities and research directions to close the gap between laboratory-scale demonstrations and real-world implementation.