ScholarWorks@동국대학교

초록

Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for devel-oping efficient pH-universal hydrogen evolution reaction (HER) electrocatalysts by overcoming the slug-gish 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 cur-rent 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 cat-alytic mechanism in alkaline media. Density functional theory calculations further reveal that such syn-ergistic effects lead to reduced free energy for an efficient water dissociation process, resulting in remarkable HER catalytic performances within universal pH environments.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

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