Effect of synthesis route on electrocatalytic water-splitting activity of MoS2/UiO-66 hybrid

Abstract

Development of a low-cost, highly active, and stable catalyst is the most challenging task for an efficient water-splitting process. In this regard, Hybrids composed of transition metals and MOF materials are an attractive possibility to be explored. Such hybrid materials show modified structures along with improved electrocatalytic performance due to the synergistic effects of the two materials. In this paper, we report UiO-66/MoS2 hybrid catalyst synthesized via two different synthesis routes. Their comparative characteristics and activity for overall water-splitting are also discussed. It was observed that Hybrid-2 showed better electrocatalytic performance with Hydrogen Evolution Reaction (HER) overpotential of 129 mV (at ƞ10) and Tafel slope of 51 mV/dec. For Oxygen Evolution Reaction (OER), it showed an overpotential of 180 mV (at ƞ10) and Tafel slope of 64 mV/dec. Moreover, the catalyst was stable for longer periods with very slight loss of activity. The improved results can be attributed to the interaction of the key characteristics of two materials which led to unique architecture of the hybrid and improved electrical connectivity with an increased exposed active surface area that assists in the transportation of charge carriers to the electrode and electrolyte interface. The results suggest that UiO-66/MoS2 hybrids are promising as active and non-expensive electrocatalytic catalyst for overall water-splitting catalyst. The findings also speculate an insight on the effect of the synthesis route on the structure and activity of MOF hybrids with robust catalytic performance.