Janus bimetallic materials as efficient electrocatalysts for hydrogen oxidation and evolution reactions

The development of hydrogen energy is limited by the high cost of platinum group metals (PGM). There is an urgent need to design efficient PGM-free electrocatalysts in the hydrogen electrode. Herein, Janus Ni/W bimetallic materials are proposed as an effective PGM-free bifunctional hydrogen electrocatalyst. By constructing the bimetallic materials, a synergistic effect is realized to enhance the reaction kinetics and improve the catalytic performance. In general, Ni can provide excellent H_ad sites, and W serves as OH_ad sites. Therefore, the synergistic effect of Ni and W can improve the kinetics of hydrogen evolution reaction and the hydroxide oxidation reaction. Ni/W@NF can obtain the hydrogen evolution reaction current density of 10 mA cm^-2 with an overpotential of only 62.6 mV, and the exchange current density of hydroxide oxidation reaction can reach 1.83 mA cm^-2. This work provides a new idea for the design of high-efficiency and low-cost PGM-free bifunctional hydrogen electrocatalysts.