Indented Cu2MoS4 nanosheets with enhanced electrocatalytic and photocatalytic activities realized through edge engineering

Abstract

Edges often play a role as active centers for catalytic reactions in some nanomaterials. Therefore it is highly desirable to enhance catalytic activity of a material through modulating the microstructure of the edges. However, the study associated with edge engineering is less investigated and still at its preliminary stage. Here we report that Cu₂MoS₄ nanosheets with indented edges can be fabricated through a simple chemical etching route at room temperature, using Cu₂MoS₄ nanosheets with flat ones as sacrifice templates. Taking the electrocatalytic hydrogen evolution reaction (HER), photocatalytic degradation of rhodamine B (RhB) and conversion of benzyl alcohol as examples, the catalytic activity of Cu₂MoS₄ indented nanosheets (INSs) obtained through edge engineering was comparatively studied with those of Cu₂MoS₄ flat nanosheets (FNSs) without any modification. The photocatalytic tests revealed that the catalytic active sites of Cu₂MoS₄ nanosheets were associated with their edges rather than basal planes. Cu₂MoS₄ INSs were endowed with larger electrochemically active surface area (ECSA), more active edges and better hydrophilicity through the edge engineering. As a result, the as-fabricated Cu₂MoS₄ INSs exhibited an excellent HER activity with a small Tafel slope of 77 mV dec⁻¹, which is among the best records for Cu₂MoS₄ catalysts. The present work demonstrated the validity of adjusting catalytic activity of the material through edge engineering and provided a new strategy for designing and developing highly efficient catalysts.