Mo_xW_1−x(S_ySe_1−y)₂ Alloy Nanoflakes for High‐Performance Electrocatalytic Hydrogen Evolution

Over years, layered transition metal dichalcogenides (TMDs) have shown vast potentials in catalyzing hydrogen evolution reaction (HER). While most current research works are exclusively focused on binary systems, very little attention has been paid to their ternary and quaternary alloys. In this work, a high‐temperature solution method is employed to prepare 25 different Mo_xW_1−x(S_ySe_1−y)₂ alloys with high yields. Resulting products are comprised of thin nanoflakes with cation and anion compositions independently tunable over the entire range. When evaluated as HER electrocatalysts in acids, these materials exhibit high activity and durability with small onset overpotentials and Tafel slopes. Furthermore, some general trend in their composition‐activity correlation is observed, and a few most active combinations successfully identified. This study may provide valuable insights in the future search of high‐performance HER electrocatalysts based on TMDs.