Single-atom catalysts supported on atomically thin materials for water splitting

Single-atom catalysts (SACs) have demonstrated exceptional performance in electrocatalytic water splitting, owing to their maximized atomic utilization efficiency and superior reaction kinetics. The incorporation of SACs typically depends on robust metal-support interactions, which stabilize the single atoms on the support through various unsaturated chemical sites or spatial confinement. A critical challenge lies in precisely modulating the electronic structure and coordination environment of metal atoms. However, current research primarily focuses on single-atom metals, often neglecting the significant role of support materials in SACs. Two-dimensional (2D) atomically thin materials (ATMs) possess unique physicochemical properties and tunable reaction environments, which can modulate catalytic performance via metal-support interactions, positioning them as promising platforms for SAC loading. This paper reviews the recent advancements and the current status of SACs supported on 2D ATMs (SACs@ATMs). The structural design theory and synthesis strategies of SACs@ATMs are systematically discussed. The significance of advanced characterization techniques in elucidating the coordination environment and metal-support interactions is highlighted. Additionally, the reaction mechanisms and applications of SACs in electrocatalytic water splitting are summarized. Finally, the future challenges and opportunities for SACs@ATMs are outlined. This paper aims to provide insights and guidance for the rational design of SACs@ATMs with high-performance electrocatalytic water splitting capabilities. Single-atom catalysts (SACs) are highly efficient for splitting water into clean energy. This review explores how pairing SACs with 2D atomically-thin materials boosts their performance. It summarizes how these catalysts are designed and made, how scientists study their structure, and their role in water splitting. The analysis also outlines future challenges and opportunities for improving these advanced catalysts.