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

MoS 2 /CoS 2 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 MoS 2 /CoS 2 heterostructures consist of layered CoS 2 and MoS 2 . The (210) facet of CoS 2 and the (002) facet of MoS 2 contacted vertically resulted in improved electrons and holes transfer in the interface. The ratios of CoS 2 /MoS 2 plays an important role to get high performance (CoS 2 /MoS 2 /NC-n%, e.g. n = 20, 25, 30, 35 wt%). Meanwhile, sample CoS 2 /MoS 2 /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 CoS 2 /MoS 2 /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.