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Efficient Hydrogen and Oxygen Evolution from Degenerate-Doped Metallic WS2 Bifunctional Electrocatalyst
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DOI:10.1002/cnma.70303.png)
Abstract
En 中文
The changes in electronic and structural properties of transition metal dichalcogenide (TMDC)-based electrocatalysts significantly affect the electrochemical water-splitting activity. Herein, we report the efficient electrochemical hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) bifunctional activity of Ru degenerate-doped metallic WS2 catalyst in alkaline electrolyte medium. WS2 with a high percentage (14%) of Ru doping exhibits degenerate semiconductor nature with a structural phase transformation from the 2H-hexagonal into the 1T-octahedral phase. The 1T-WS2 degenerate semiconductor (WS2@Ru14) catalyst demonstrates excellent bifunctional activity in 1 M KOH electrolyte with low overpotential ( η10 = 112 mV vs. reversible hydrogen electrode [RHE] and 470 mV vs. RHE) and low Tafel slope (b = 37 and 42 mV dec−1) for HER and OER activity, respectively. Further, the symmetric full-cell electrolyzer constructed with a WS2@Ru14 catalyst used as an anode and cathode for overall water splitting requires a cell voltage of 1.68 V to deliver a 10 mA cm−2 current density. The WS2@Ru14 catalyst with high carrier density and intrinsic conductivity activates the basal plane and promotes electrochemical activity with fast electron transfer kinetics in the degenerate-doped metallic WS2 semiconductor. The density functional theory calculations throw light on understanding the phase stability and electronic band structure of the heavily doped WS2 semiconductor. This work opens an avenue for rational design of doped TMDC electrocatalysts for clean energy generation.
Keywords:
degenerate doping
electrocatalyst
hydrogen evolution reaction
phase transition
tungsten disulfide
water splitting
Journal
IF:
2.6
Papers:
645
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3.8K
