MoS2/CoS2 heterostructures embedded in N-doped carbon nanosheets towards enhanced hydrogen evolution reaction

MoS2/CoS2 heterostructures on nitrogen-doped carbon nanosheets as an efficient electrocatalyst for hydrogen evolution reaction (HER) are prepared using zeolitic imidazolate frameworks-67 as precursors. Two dimensional (2D)/2D MoS2/CoS2 heterostructures consist of layered CoS2 and MoS2. The (210) facet of CoS2 and the (002) facet of MoS2 contacted vertically resulted in improved electrons and holes transfer in the interface. The ratios of CoS2/MoS2 plays an important role to get high performance (CoS2/MoS2/NC-n%, e.g. n = 20, 25, 30, 35 wt%). Meanwhile, sample CoS2/MoS2/NC-25% revealed the best HER activity, suggesting the sample has the largest number of active sites and the fastest electron transfer rate. In addition, sample CoS2/MoS2/NC-25% exhibited the lowest onset potential of 51 mV, the lowest potential of 215 mV at 10 mA cm−2, and the smallest Tafel slope of 80.0 mV dec−1. The result is utilizable for the construction of heterostructures with excellent HER performance.