1T‐MoS2 Enriched Hierarchical MoS2/MoO3 Produced by Phase Transformation for Efficient Hydrogen Evolution Reaction

Abstract In recent years, transition metal sulfides have been widely studied in the context of their use as electrocatalysts. The electrocatalytic propensity of the classical semiconductor MoS2, which exists in the 1T and 2H phase structures, has attracted extensive attention. Therefore, the synthesis of highly active and stable MoS2‐based catalysts has become the goal of many research efforts. We recently developed a method that can be utilized to prepare the MoS2/MoO3 heterojunction in a phase‐controlled manner. 1T‐MoS2 phase enriched MoS2/MoO3 heterojunction can be generated using a simple hydrothermal and acid treatment sequence and that the heterojunction has a unique three‐dimensional structure, large active surface area, and therefore achieve a low overpotential and high catalytic current density, as well as long‐term stability for the hydrogen evolution reaction.