Hydrothermally synthesized MoSe2/ZnO composite with enhanced hydrogen evolution reaction

Efficient hydrogen evolution reaction is going to be the primary sustainable source of energy in the future. To achieve this, non-metal catalysts are required to replace the cutting-edge catalysts like platinum with affordable earth-abundant and long-lasting electrocatalysts. For efficient hydrogen evolution reaction, 1T phase of MoSe2 nanosheets has been found to display superior catalytic properties due to exposed edges. Unfortunately, the catalytic activity of such nanosheets for hydrogen evolution reaction is limited due to inevitable agglomeration and stacking of the liquid exfoliated nanosheets and their intrinsic lower conductivity. In order to mitigate these issues composites with other low dimensional materials have shown enhanced catalytic performance. Here, in this study, we describe such a composite using MoSe2 and ZnO. Out of various compositions, the one with a MoSe2 and ZnO with weight ratio 2:1 outperformed in terms of enhanced electrocatalytic activity. This sample displayed lower overpotential (0.25 V at 10 mA/cm2), and onset potential (0.11 V at 1 mA/cm2). As a result, the reaction kinetics are consistent with the Volmer-Heyrovsky mechanism, as indicated by the lower Tafel slope of 87 mV/dec. In addition, optimized composite also exhibit larger effective surface area, higher turnover frequency (0.81 s−1) and lower charge transfer contact resistance. Thus heterojunction between TMDC's and semiconductor oxides may create new pathways for enhancing the HER activity.