Progress on 2D-2D heterostructured hybrid materials for efficient electrocatalysis

Two-dimensional (2D) materials are widely used in many energy conversion reactions, especially 2D-2D heterostructured hybrid materials that have been extensively investigated in recent years. In this review article, we provide a comprehensive review of the recent research progress on 2D-2D hybrid materials, starting from the introduction of these emerging hybrids. Then, the fabrication strategies are discussed with their pros and cons. Furthermore, the techniques, especially those for heterointerface characterization, are highlighted. Afterward, the applications of these 2D-2D heterostructured hybrid materials in energy conversion reactions with representative examples in the last five years are discussed and summarized. Finally, a summary and perspectives for realizing the rational design and synthesis of 2D-2D hybrids as advanced electrocatalysts towards active and stable energy conversion reactions are provided. 2D-2D hybrids have large heterointerfaces and strong interactions between the two components, leading to strong coupling effects that influence the electronic structure of active sites and benefit charge transfer during energy conversion reactions.