Heterogeneous Photocatalysts Based on g-C₃N₄: Innovations and Applications in Sustainable Energy Conversion and Storage

Heterogeneous photocatalysts are utilized as a novel technology in energy conversion and storage, particularly in sustainable and green solar fuels, as well as in a variety of environmental applications. Graphitic carbon nitride (g-C₃N₄) photocatalysts form a specific group of heterogeneous photocatalysts due to their unique physicochemical, optical, and electrical properties. In this review, the fundamental mechanisms of heterogeneous photocatalysts, their advantages, challenges, and the design of g-C₃N₄-based photocatalysts are examined. The structural properties, surface physicochemical characteristics, surface stability, as well as their electrochemical, photoelectrochemical, and optical properties are highlighted. Key applications, such as pollutant degradation, carbon dioxide reduction, certain organic transformations, and disinfection, are also addressed. By reviewing significant advancements in this field, new opportunities for the design and fabrication of highly efficient g-C₃N₄-based photocatalysts for diverse applications are expected to arise.