Highly active hydrogen evolution facilitated by topological surface states on a Pd/SnTe heterostructure
Qing Qu, Bin Liu, Wing Sum Lau, Ding Pan, I. K. Sou
Abstract
Topological quantum materials have emerged as promising electrocatalysts for hydrogen evolution reaction (HER). However, most of their performance is behind noble metals such as benchmark platinum (Pt). Here, we report a molecular-beam-epitaxy- and electron-beam-evaporation-grown Pd(20nm)/SnTe(70nm) heterostructure that displays a higher electrocatalytic activity than that of a pure Pd(20nm) thin film, and higher than that of a commercial Pt foil. Density functional theory calculations show that the topological surface states (TSSs) of the SnTe (001) play a key role. Electron transfer from both Pd and adsorbed H atoms to the TSSs results in weaker Pd-H binding and more favorable ΔGH. Our work demonstrates that a metal/topological material heterostructure could be a prominent catalyst to enjoy HER activity outperforming that of Pt and offers a promising direction to optimize the performance of electrocatalysts based on topological quantum materials.