Recent advances in metal-free CDs/g-C3N4 photocatalysts: Synthetic strategies, mechanism insight, and applications

Abstract

Carbon dots/graphite carbon nitride (CDs/g-C3N4), a novel composite photocatalyst, has shown great potential for applications in energy regeneration and environmental remediation owing to its following advantages: metal-free, low cost, easily tunable, and excellent photocatalytic performance. Hence, we reviewed the development of synthetic strategies, photocatalytic enhancement mechanisms, and photocatalytic applications of CDs/g-C3N4 in this study. First, the three composite strategies of CDs and g-C3N4-self-assembly, solvothermal, and calcination polymerization are outlined, and their advantages and disadvantages are described in detail. Moreover, the photocatalytic enhancement mechanism of the composite strategies was elucidated according to the variation trends of CDs/g-C3N4 band structure, electronic properties, light absorption range, and interfacial charge transfer. Then, the applications of CDs/g-C3N4 in hydrogen evolution, pollutant degradation, CO2 reduction, and bacterial disinfection in recent years are reviewed systematically. Finally, the current obstacles and future research directions of CDs/g-C3N4 are discussed from the perspective of preparation technology and practical applications, respectively.