Exploring nanoengineering strategies for the preparation of graphitic carbon nitride nanostructures

Graphitic carbon nitride (g-C3N4) is a metal-free semiconductor that has drawn considerable attention due to its remarkable photoactivity under visible light irradiation, becoming one of the most promising photocatalytic materials in recent years. However, the photocatalytic performance of bulk g-C3N4 is quite limited due to its irregular morphology, low surface area, and rapid recombination of photogenerated charge carriers. Several strategies have been developed to overcome these drawbacks, where morphological control has played a crucial role. In this review, novel nanoengineering strategies for the synthesis of well-defined g-C3N4 nanostructures are explored and discussed in detail. Strategies such as exfoliation of bulk material, ionic-liquid assisted synthesis, confinement of nitrogen-rich organic precursors in inorganic salts, use of dynamic gas templates, and design of supramolecular precursors, lead to nano and micrometric morphologies that exhibit outstanding photocatalytic properties. Finally, summary comments and a future perspective on the design of novel g-C3N4 morphologies are noted. This review is expected to provide a comprehensive and timely summary of the morphological control of graphitic carbon nitride, leading to a better rational design that improves its performance in photocatalytic processes.