C₃N₅-based nanomaterials and their applications in heterogeneous catalysts, energy harvesting, and environmental remediation

Over the past few decades, the global reliance on fossil fuels and the exponential growth of human population have escalated global energy consumption and environmental issues. To tackle these dual challenges, metal catalysts, in particular precious metal ones, have emerged as pivotal players in the fields of environment and energy. Among the numerous metal-free and organic catalyst materials, C₃N₅-based materials have a major advantage over their carbon nitride (CxNy) counterparts owing to the abundant availability of raw materials, non-toxicity, non-hazardous nature, and exceptional performance. Although significant efforts have been dedicated to synthesising and optimising the applicable properties of C₃N₅-based materials in recent years, a comprehensive summary of the immediate parameters of this promising material is still lacking. Given the rapid development of C₃N₅-based materials, a timely review is essential for staying updated on their strengths and weaknesses across various applications, as well as providing guidance for designing efficient catalysts. In this study, we present an extensive overview of recent advancements in C₃N₅-based materials, encompassing their physicochemical properties, major synthetic methods, and applications in photocatalysis, electrocatalysis, and adsorption, among others. This systematic review effectively summarises both the advantages and shortcomings associated with C₃N₅-based materials for energy and environmental applications, thus offering researchers focussed on CxNy-materials an in-depth understanding of those based on C₃N₅. Finally, considering the limitations and deficiencies of C₃N₅-based materials, we have proposed enhancement schemes and strategies, while presenting personal perspectives on the challenges and future directions for C₃N₅. Our ultimate aim is to provide valuable insights for the research community in this field.