Novel ternary metals-based telluride electrocatalyst with synergistic effects of high valence non-3d metal and oxophilic Te for pH-universal hydrogen evolution reaction

Abstract

Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction (HER) electrocatalysts by overcoming the sluggish alkaline HER kinetics. Here, we design ternary transition metals-based nickel telluride (MoWNiTe) catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism. The MoWNiTe showed excellent HER catalytic performance with overpotentials of 72, 125, and 182 mV to reach the current densities of 10, 100, and 1000 mA cm−2, respectively, and the corresponding Tafel slope of 47, 52, and 58 mV dec−1 in alkaline media, which is much superior to commercial Pt/C. Additionally, the HER performance of MoWNiTe is well maintained up to 3000 h at the current density of 100 mA cm−2. It is further demonstrated that the MoWNiTe exhibits remarkable HER activities with an overpotential of 45 mV (31 mV) and Tafel slope of 60 mV dec−1 (34 mV dec−1) at 10 mA cm−2 in neutral (acid) media. The superior HER performance of MoWNiTe is attributed to the electronic structure modulation, inducing highly active low valence states by the incorporation of high valence non-3d transition metals. It is also attributed to the oxophilic effect of Te, accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media. Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process, resulting in remarkable HER catalytic performances within universal pH environments.