Lateral Heterostructures of Defect-Patterned MoS2 for Efficient Hydrogen Production

Abstract

Defect engineering has demonstrated significant potential in optimizing the catalytic performance of molybdenum disulfide (MoS₂) for hydrogen evolution reaction (HER). The simultaneous control of defect type, concentration, and spatial distribution within a single domain is crucial for accurate experimental detection and the establishment of structure-performance relationships, yet it remains challenging. Here, an efficient one-pot chemical vapor deposition (CVD) method is presented to synthesize monolayer defect-patterned MoS₂ with alternating domains of varying Mo vacancy (V_Mo) concentrations, along with trace tellurium (Te) doping at the edges, forming MoS₂-MoS_2xTe_2(1-x) lateral heterostructures (LHS). A single defect patterned LHS-based on-chip electrochemical microcell, utilizing graphene as an intermediate contact, is employed to extract HER activity and achieve higher reaction kinetic than pristine MoS₂. These findings demonstrate that the synergistic effect of V_Mo and Te doping effectively activates more unsaturated sulfur atoms, facilitating proton adsorption and accelerating the HER process. This work enriches the point defect engineering and provides valuable insights for the design and synthesis of 2D semiconductor catalysts.

Keywords: HER; Mo vacancy; MoS2; Te doping; lateral heterostructure.