Bionic Structural Design and Electrochemical Manufacture of WC/N-Doped Carbon Hybrids as Efficient ORR Catalyst

A biomass-derived WC/N-doped carbon nanocomposite (denoted as WC/CC) with unique bionic structures, as an efficient electrocatalyst toward oxygen reduction reaction (ORR), is simply prepared via an eco-friendly and scalable method in molten NaCl-KCl using bulk-WS2 as a precursor. Corn crumb (CC) from by-products of food industry provides a fibriform N-containing biochar backbone by in situ pyrolysis, while W from the in situ electroreduction of WS2 would infiltrate into the carbon matrix under the effect of an applied electric field, contributing to the crystallization of WC along the fibers so that gnarled root-like composites are fabricated. The electrocatalytic behavior of the prepared materials are investigated in detail, the optimized sample (WC/CC-1/2) exhibits a decent onset potential of 0.865 V vs RHE for ORR in 1 M KOH solution and a four-electron pathway is dominant. This work provides a simple and feasible strategy for synthesizing high-performance ORR catalysts using biochar templates.