Fabrication of Te@NiTe2/NiS heterostructures for electrocatalytic hydrogen evolution reaction

Abstract Transition metal chalcogenides are promising hydrogen evolution reaction (HER) electrocatalysts; however, their performance still needs to be improved to meet the requirements of practical applications. Herein, an interface-engineering strategy is exploited to prepare efficient transition metal chalcogenide based HER catalysts in alkaline medium. Specifically, the heterogeneous nanostructure of 1D core-shell Te@NiTe2 and 2D NiS (Te@NiTe2/NiS) has been fabricated by an easy one-step solvothermal method. The HER activity of Te@NiTe2/NiS is optimized by adjusting the ratio of raw materials and reaction time. Under the optimum conditions, the Te@NiTe2/NiS displays higher HER activity than individual Te@NiTe2 and NiS in alkaline medium and the reasons are investigated in detail. To improve the HER activity of Te@NiTe2/NiS, the Te@NiTe2/NiS is further combined with conductive acetylene black (AB) by physically mixing. The resulting Te@NiTe2/NiS/AB has a low overpotential at 10 mA/cm2 of 101 mV, higher current density than 20% Pt/C when the overpotential is larger than 0.37 V and good long-term stability, indicating its practicability as HER electrocatalysts. This work presents the validity of interface-engineering strategy in preparing highly efficient transition metal chalcogenides based HER electrocatalysts.