High-Efficiency Electrochemical Hydrogen Evolution Catalyzed by Tungsten Phosphide Submicroparticles

The development of high-efficiency non-noble-metal hydrogen evolution reaction (HER) electrocatalysts operating at all pH values is highly desired but still remains a challenge. In this letter, we report on developing tungsten phosphide submicroparticles as a high-efficiency HER catalyst with high durability for electrochemical hydrogen generation in acidic water. This catalyst shows a low onset overpotential of 54 mV, a Tafel slope of 57 mV/dec, an exchange current density of 0.017 mA/cm2, and nearly 100% Faradaic efficiency. It needs overpotentials of 115 and 161 mV to afford current densities of 2 and 10 mA/cm2, respectively. Moreover, this catalyst is also good in activity and durability under neutral and basic conditions.