Nitrogen-based imperfections in graphitic carbon nitride - new trend for enhancing photocatalytic activity?

Abstract

This review comprehensively explores the engineering of nitrogen vacancies (N-vacancies) in polymeric carbon nitride (CN) and uncovering their profound impact on the photocatalytic applications of CN. The intentional creation of N-vacancies in CN obtained by removing the targeted N atoms emerges as a crucial strategy for fine-tuning its photo(catalytic)physical properties. Defect-centric investigations illuminate enlarged surface areas, increased substrate interactions and spotlight the correlation between N-vacancy and photoredox transformations. Key N-vacancies (NHx, N2C, N3C) play exceptional roles in elevating the photocatalytic activity of CN. Besides comprehensively navigating the competitive literature of CN research, this review highlights the controlled manipulation of N-vacancies in CN as an instrumental avenue for customized property tailoring. Additionally, it provides a perspective on the generation of N-vacancies considering temperature, time, and reaction atmosphere by inspecting available synthesis strategies, particularly thermal treatments, along with advanced characterization techniques shedding light on the profound influence of N-vacancies on the structural and electronic properties of CN. Moreover, this review underlines the impact of defects in CN on its photocatalytic performance, tuning bandgaps, midgap state formation, and creating active sites within the lattice. The versatile strategy employed in vacancy engineering within CN shows great potential for designing new-generation photocatalysts with tailored functionalities. This review provides a perspective for researchers in the relevant field by depicting the challenges, providing an insightful perspective, and exploring future directions aimed at catalyzing advances in the field of N-vacancy CN for various photocatalytic applications.