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Highly improved electrocatalytic activity of NiSx: Effects of Cr-doping and phase transition
- Source :
- Applied Catalysis B: Environmental. 267:118721
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- Hydrogen evolution reaction (HER) is a vital step for electrochemical energy conversion technologies. However, developing cost-efficient electrocatalysts remains a huge challenge. Here, we report that Cr-doped NiSx (Cr-NiSx) in situ grown on Ni foam via a hydrothermal sulfurization reaction can be an ultra-highly efficient and low-cost electrocatalyst for HER in alkaline condition. We find that the Cr-doping can trigger the formation of NiS and NiS1.19, leading to the suppression of Ni3S2 in the nanostructure. We show that Cr-NiSx exhibits an excellent HER activity with an ultralow overpotential of 81 mV at 10 mA cm−2, better than those of most nickel sulfide catalysts, and good stability. Our combined experimental and computational study reveals that the excellent performance is contributed by: (1) stabilized NiSx phase, (2) strongly improved conductivity, (3) greatly enhanced active sites, and (4) reduced Gibbs free energy for hydrogen adsorption (ΔGH) due to the Cr-doping. We believe that this work provides a simple approach to design cost-effective and ultra-highly efficient HER electrocatalysts for practical applications.
- Subjects :
- Materials science
Nanostructure
Nickel sulfide
Process Chemistry and Technology
02 engineering and technology
Overpotential
010402 general chemistry
021001 nanoscience & nanotechnology
Electrocatalyst
01 natural sciences
Electrochemical energy conversion
Catalysis
0104 chemical sciences
Gibbs free energy
symbols.namesake
chemistry.chemical_compound
Chemical engineering
chemistry
Phase (matter)
symbols
0210 nano-technology
General Environmental Science
Subjects
Details
- ISSN :
- 09263373
- Volume :
- 267
- Database :
- OpenAIRE
- Journal :
- Applied Catalysis B: Environmental
- Accession number :
- edsair.doi...........92ee6eff8fc4f0f59ce91ff0d927ef5b