An overview of the current progress of graphitic carbon nitride and its multifunctional applications

Graphitic carbon nitride (g-C3N4) has spared tremendous study as a new-generation non-metallic photocatalyst in a variety of industrial applications due to its remarkable optoelectronic features, natural abundance and high stability. However, pristine g-C3N4 suffers from some shortcomings of low specific surface area, fast recombination of photo-generated carriers, poor electric conductivity and limited photo-response range. A lot of efforts have been made to overcome these disadvantages. Herein, this review focuses on the current progress of g-C3N4 and its multifunctional applications. After brief overview of traditional synthesis methods for various morphological g-C3N4, recent advance on g-C3N4 fabrication techniques, such as supramolecular self-assembly, microwave-assisted synthesis, and molten salt synthesis, is highlighted. A series of modification strategies, including doping, defect, heterojunction and surface engineering of g-C3N4 have been summarized. Moreover, the importance of employing theoretical methodologies to comprehend the distinctive characteristics of g-C3N4 and its derivatives, is emphasized. The up-to-date status for g-C3N4 applications in gas sensing/detection, white light emission diodes, perovskite solar cells, hydrogen production and photocatalytic pollution degradation is addressed. Finally, the challenges and future perspective on g-C3N4 research are presented as well. This assessment will help to elaborate the relationship of structure, morphology, modification and applications of g-C3N4 for potential developments.