Recent advancements and opportunities of decorated graphitic carbon nitride toward solar fuel production and beyond

Recent advances have revealed the potentials of rationally designed graphitic carbon nitride (g-C3N4) for the photocatalytic H2 evolution reaction due to its unique morphological structure and appealing electronic and physicochemical properties. In this review, we introduce the basic principles of the photocatalytic overall water splitting, the advantages and challenges of g-C3N4-based photocatalysts. The unique electronic, crystal structure, surface physicochemical, and adsorption properties of g-C3N4-based photocatalysts are discussed to provide insightful prospects on charge dynamics. This is followed by a comprehensive overview of the recent developments of g-C3N4 for photocatalytic reactions, particularly focusing on various tailoring strategies, which include: (1) heterojunction design, g-C3N4/semiconductor heterojunction, Z-scheme heterojunction, and g-C3N4/metal heterojunction (cocatalyst), (2) functionality design at the atomic level, such as elemental doping, and (3) nanostructure architecting by tuning the dimensionality of g-C3N4 that affects photoactivity. In addition, some fundamental issues and challenges in each of the aforementioned strategies are also highlighted. The advancements of the photo-redox applications toward water splitting, CO2 photoreduction, and N2 photo-fixation are also presented. This review is expected to provide impactful guidelines and ideas to readers in this field on the development of g-C3N4. Moreover, it is a useful information for the development of future design strategies.