“…Among these earth-abundant candidates, 2D layered transition metal dichalcogenide nanostructures with a general formula MX 2 (where M is Mo or W, and X stands for S or Se) have been confirmed to be highly prominent categories of HER nanomaterials due to their reasonable price, distinct physicochemical properties, befitting hydrogen adsorption energy, and controllable morphological and interfacial engineering. 21–25 In particular, for MoSe 2 , the sandwiched Se–Mo–Se basal planes along the c -axis are bonded together by a van der Waals force, which verges to minimize surface free energy by exposing the basal planes as terminating surfaces, offering a possibility for diversity to enhance the electrochemical activity and expose more active edge sites. 26–31 Previously, studies have been conducted to improve the HER performance of MoSe 2 via the development of highly active Se vacancies, 32–34 heteroatom incorporation, 34,35 and electronic regulation by constructing alloys, 36–38 but the alkaline HER activity of MoSe 2 is far from satisfactory compared with commercial benchmarks.…”