Preparation of WC film on tungsten plate via molten salts electrochemistry for electrocatalytic hydrogen evolution

The development of non-precious metal electrocatalysts is an effective approach to achieving environmentally friendly electrolytic water for hydrogen production. In this paper, we report a method for the rapid preparation of excellent HER activity and durable WC thin-film electrodes using one-pot electrolysis with K2CO3 - Na2CO3 molten salts. During the electrolysis, soluble carbonate anions reduced and in situ formed WC nanoparticles on a tungsten cathode, which become firmly immobilized on the surface of the tungsten cathode, resulting in the formation of the WC/W electrode. The WC/W electrode exhibited efficient electrocatalytic HER activity, good reaction kinetics and long-term stability. In particular, the WC/W-3.1 V catalysts exhibited low overpotentials (127 mV and 221 mV) at current densities of 10 mA cm(-2) and 50 mA cm(-2), along with a small Tafel slopes (129.00 mV dec(-1)). The experimental results indicate that the WC/W electrode possesses more electrochemical active site, faster electron transfer rate and strong interfacial interaction and stability. This binder-free WC thin film electrode rapid preparation method via molten salts electrolysis provides a new approach for the development of highly active electrocatalysts.