Tungsten carbide hollow microspheres with robust and stable electrocatalytic activity toward hydrogen evolution reaction

Abstract

Here, we report a stable tungsten carbide hollow microsphere (W 2 C-HS) electrocatalyst with robust electrocatalytic activity toward hydrogen evolution reaction fabricated from carburization of tungsten oxides at 700 °C with CH 4 /H 2 flow, which demands overpotentials of 153 and 264 mV to deliver 10 and 100 mA cm -2 ascribing to the hollow structures beneficial for interfacial charge transfer as well as releasing of hydrogen molecular. Meanwhile, the W 2 C-HS electrocatalyst exhibits undetectable degradation after 20 000 potential cycles indicative of extraordinary durability; in contrast, overpotential@100 mA cm -2 is dramatically increased from 128 to 251 mV after only 2000 potential cycles for benchmark platinum electrocatalyst.