Recent advances in graphitic carbon nitride semiconductor: Structure, synthesis and applications

Carbon-based polymeric material g-C3N4 is a metal-free semiconductor and gaining great attention due to abundance of raw materials, controllable appearance, tuneable optical properties, low friction coefficient, chemical inertness, and hardness. The unique structure of g-C3N4 provided by nitrogen lone pair interaction with pi states offers g-C3N4 the most promising material for various applications. Numerous g-C3N4 based heterojunctions and homojunctions materials have been prepared with enhanced photocatalytic performance. The review examines the journey of synthesis from bulk to 1D, 0D, 2D, 3D g-C3N4 nanomaterials and their synthesis strategies along with advantages and limitations of each material. Further, the review highlights different composites of g-C3N4, modifications of g-C3N4 and their potential applications in the fields of renewable energy, energy storage and pollution control etc. Each application is explained extensively such as water splitting, pesticide and dye removal, CO2, and Cr (VI) reduction, DSSC, and sensors. Additionally, the existing challenges and their possible solutions strategies are discussed to prepare highly efficient g-C3N4. Finally, the review reveals the future prospects of g-C3N4 to improve its spectral response in visible light, structural modifications, green synthesis methods, etc. We expect that this review article will help in the evolution of new insights for the synthetic alterations and possible applications of g-C3N4 materials.