Tungsten-coated nano-boron carbide as a non-noble metal bifunctional electrocatalyst for oxygen evolution and hydrogen evolution reactions in alkaline media.

Herein, tungsten-coated nano-boron carbide (W-WB-WC/BC) particles were prepared by heating a mixture of BC and W powder using a spark plasma coating (SPC) method. During the discharge treatment process, metal W in the mixture is activated and reacts with BC to form WC, WB, and graphite nanoribbons. The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance of W-WB-WC/BC is tested in an alkaline solution, and the results show that the W-WB-WC/BC composite electrocatalyst exhibits a low overpotential of 0.36 V at 10 mA cm for the OER, a small overpotential of -0.19 V (j = 10 mA cm) for the HER, as well as good stability. The significantly enhanced electrocatalytic performance of the W-WB-WC/BC composites is attributed to their unique structure, in which WC and WB not only improve the catalytic activity for the OER and HER, but also effectively anchor the W coating on the substrate.