Enhancing electrocatalytic hydrogen evolution of WTe2 by formation of amorphous phosphate nanoshells

Abstract

Recently, designing new catalysts based on topological quantum materials has attracted much research interest. Here, we have explored WTe2, a type-II Weyl semimetal, as an effective electrocatalyst for hydrogen evolution reaction (HER). New nanostructure am-WPO@WTe2 has been constructed based on WTe2, in which the crystalline P-doped WTe2 core is covered by amorphous phosphate species. Due to the unique core-shell structure, the HER catalytic performance of am-WPO@WTe2 has been greatly enhanced, delivering a low overpotential of 220 mV and 280 mV at the current density of 10 mA/cm2 in acidic and alkaline electrolytes, respectively, with outstanding durability. The improved HER electrocatalytic performance could be attributed to the abundant active sites provided by the amorphous phosphate on the surface of the catalyst and the enhanced electron transfer due to the crystalline P-doped WTe2 core. This strategy of surface modification of Weyl semimetal may open new opportunities in utilizing topological quantum materials for application in catalysis.