Tailoring Graphitic Carbon Nitride (g‐C 3 N 4 ) for Multifunctional Applications: Strategies for Overcoming Challenges in Catalysis and Energy Conversion

Graphitic carbon nitride (g‐C 3 N 4 ) has been emerging as a promising material, and this review covers its synthesis, modifications, and applications. The synthesis of g‐C 3 N 4 comprises the use of oxygen‐free, nitrogen‐rich precursors and several modification approaches to address limitations, such as low surface area, rapid recombination of electron holes, and low sunlight absorption. These strategies consist in converting g‐C 3 N 4 into various morphologies like nanosheets, mesoporous structures, nanotubes, nanowires, nanorods, quantum dots (QDs), and thin films to create 1D, 2D, and 3D structures. The review further investigates improvement strategies, including doping, defect introduction, heterojunction formation, and coupling with carbonaceous materials, which enhance g‐C 3 N 4 characteristics and broaden its use. These changes enable g‐C 3 N 4 to be applied in a wide range of photocatalytic (H 2 production, CO 2 reduction, photoinduced bacterial disinfection, and water treatment) and noncatalytic (drug delivery, H 2 O 2 production, energy storage, N 2 fixation, organic synthesis, and sensor technology) applications. Addressing key challenges, such as synthesis complexity, environmental concerns, and material stability is essential, and the review outlines the prospects for future research to overcome the g‐C 3 N 4 limitations and realize its full potential. This review will assist researchers to understand and explore further the synthesis, modification strategies, and applications of g‐C₃N 4 in energy, environment, and healthcare.