Semiconductor-based photocatalysis, particularly with graphitic carbon nitride (g-C3N4), has gained significant attention for hydrogen evolution, CO2 reduction, organic synthesis, and pollutant remediation due to its unique properties. The preparation of g-C3N4 through solid-phase polymerization of organic precursors at high temperatures often results in limited performance due to poor control over polymerization. Various strategies such as elemental doping, morphology modulation, and defect creation are being explored to enhance the catalytic activity of g-C3N4. Recent studies have shown that the addition of specific organic or inorganic molecules like oxalic acid can effectively improve the photocatalytic performance of g-C3N4. Additionally, transition metal sulfides like MoS2, NiS, and CoS are being investigated as cocatalysts to promote hydrogen evolution on g-C3N4, with bimetal sulfides showing enhanced charge separation efficiency. Research is also focusing on utilizing water as a solvent to improve the synthesis of g-C3N4, leading to the formation of highly active catalysts with improved properties. Overall, these advancements in tuning the structure and composition of g-C3N4 show promising results in enhancing its photocatalytic activity for various applications, particularly in hydrogen evolution and pollutant remediation.