Synthesis and Catalytic Advances of 2D Hexagonal Noble-Metal Nanostructures

Noble-metal nanomaterials are widely used as electrocatalysts because of their high activity and stability. And properties of materials are related to their size and morphology, endowing the morphology and size-controlled synthesis for noble-metal nanomaterials to be a hotspot in varied fields. 2D hexagonal nanostructures possess unique electronic and physical properties including high electrical conductivity, chemical stability, large specific surface area. Consequently, the composites of 2D hexagonal nanostructures with noble-metal nanomaterials can not only retain the dominances of individual domains but also acquire benefits from their synergy, which may generate additional active sites and further enhance the activity of individual sites. Thus 2D hexagonal noble-metal (HNM) nanomaterials exhibit enormous potential to significantly boost catalytic activity in electrocatalysis. In this review, the unique advantages of 2D HNM nanostructures in advanced applications are introduced first. Subsequently, the classification, commonly synthetic approaches, factors affecting the formation, and the applications of 2D HNM nanostructures in different catalytic reactions are summarized in detail. Finally, the future prospects of 2D HNM nanostructures for advanced applications are discussed. The review not only provide a comprehensive insight over relationship of structure and performance for 2D HNM but also raise guidance on designing electrocatalysts with outstanding performance.