Synergizing lattice strain and electron transfer in TMSs@ 1 T-MoS2 in-plane heterostructures for efficient hydrogen evolution reaction

The 1 T phase molybdenum disulfide (1 T-MoS2) is considered a promising candidate to replace Pt-based catalysts for the hydrogen evolution reaction (HER). However, the less-active sites on the basal plane limit its electrocatalytic activity. Herein, we designed an in-plane heterostructure with transition metal sulfide (TMSs) clusters embedded in the 1 T-MoS2 nanosheets by substituting a portion of MoS2 nanodomains (TMSs@1 T-MoS2). Experimental and DFT results suggest that this unique structure induces lattice distortion of 1 T-MoS2 and electron transfer at the heterointerfaces from the TMSs to the 1 T-MoS2. Both factors synergistically regulate the electronic structure of the basal plane, thus improving hydrogen adsorption. Consequently, the TMSs@ 1 T-MoS2 exhibited significantly enhanced HER activity. In particular, NiS2 @ 1 T-MoS2 delivered 10 mA cm−2 at low overpotentials of 73 mV and 71 mV in 0.5 M H2SO4 and 1.0 M KOH, respectively.