Photocatalysis plays a vital role in sustainable energy conversion and environmental remediation because of its economic, eco-friendly, and effective characteristics. Nitrogen-rich graphitic carbon nitride (g-C3N5) has received worldwide interest owing to its facile accessibility, metal-free nature, and appealing electronic band structure. This review summarizes the latest progress for g-C3N5-based photocatalysts in energy and environmental applications. It begins with the synthesis of pristine g-C3N5 materials with various topologies, followed by several engineering strategies for g-C3N5, such as elemental doping, defect engineering, and heterojunction creation. In addition, the applications in energy conversion (H2 evolution, CO2 reduction, and N2 fixation) and environmental remediation (NO purification and aqueous pollutant degradation) are discussed. Finally, a summary and some inspiring perspectives on the challenges and possibilities of g-C3N5-based materials are presented. It is believed that this review will promote the development of emerging g-C3N5-based photocatalysts for more efficiency in energy conversion and environmental remediation.
Keywords: defect engineering; energy conversion; environmental remediation; heterojunction; nitrogen-rich graphitic carbon nitride.