Plant polyphenol-involved coordination assembly-derived Mo3Co3C/Mo2C/Co@NC with phase regulation and interface engineering for efficient hydrogen evolution reaction electrocatalysis

The rational exploration of highly active and low-cost materials for electrocatalytic hydrogen evolution is extremely imperative, but remains challenging as well. Transition metal carbides (TMCs) as highlighted electrocatalysts usually exhibit unsatisfactory activity and stability. In this work, we demonstrate a two-step strategy for electrocatalyst synthesis involving biomass-derived tannic acid (TA) and coordination assembly preparation followed by subsequent high-temperature carbonization. Interestingly, by simply controlling the feed amount of TA, heterostructured nitrogen-doped graphene-coated Mo3Co3C-based tri- and bi-component electrocatalysts (Mo3Co3C/Mo2C/Co@NC and Mo3Co3C/Co@NC) can be obtained with phase regulation and interface engineering. It is observed that the heterostructured materials possess more active sites than that of the TMC-excluding sample (Co@NC). Moreover, the tri-component Mo3Co3C/Mo2C/Co@NC may enhance the intrinsic activity at each active site due to the strong interaction at the Mo3Co3C/Mo2C interface. These advantages allow the Mo3Co3C/Mo2C/Co@NC catalyst to deliver superior electrocatalytic activity and favorable kinetics towards the HER, with a low overpotential of 211 mV and a Tafel slope of 96.0 mV dec(-1). Furthermore, it has good long-term stability. This work provides new inspiration for heterostructured TMC-based electrocatalysts with high performance towards promising catalytic applications.