Advanced carbon nitride‐based single‐atom photocatalysts

Single‐atom catalysts (SACs) have rapidly become a hot topic in photocatalytic research due to their unique physical and chemical properties, high activity, and high selectivity. Among many semiconductor carriers, the special structure of carbon nitride (C3N4) perfectly meets the substrate requirements for stabilizing SACs; they can also compensate for the photocatalytic defects of C3N4 materials by modifying energy bands and electronic structures. Therefore, developing advanced C3N4‐based SACs is of great significance. In this review, we focus on elucidating efficient preparation strategies and the burgeoning photocatalytic applications of C3N4‐based SACs. We also outline prospective strategies for enhancing the performance of SACs and C3N4‐based SACs in the future. A comprehensive array of methodologies is presented for identifying and characterizing C3N4‐based SACs. This includes an exploration of potential atomic catalytic mechanisms through the simulation and regulation of atomic catalytic behaviors and the synergistic effects of single or multiple sites. Subsequently, a forward‐looking perspective is adopted to contemplate the future prospects and challenges associated with C3N4‐based SACs. This encompasses considerations, such as atomic loading, regulatory design, and the integration of machine learning techniques. It is anticipated that this review will stimulate novel insights into the synthesis of high‐load and durable SACs, thereby providing theoretical groundwork for scalable and controllable applications in the field.