Water electrolysis is one of the most promising methods to produce H and O as high potential fuels. Comparing the two half-reactions, the oxygen evolution reaction (OER) is the more difficult to be optimized and still relies on expensive noble metal-based catalysts such as Ru or Ir. In this paper, we prepared nanoparticles of HfN and Hf ON and tested them for the OER for the first time. The HfN sample, in particular, showed the highest activity, requiring an overpotential of only 358 mV at 10 mA cm in Fe-free electrolyte and, above all, exhibiting long-term stability. This result places this system amongst one of the most promising catalysts for OER tested to date, in terms of sustainability, activity and stability. The prepared nanoparticles are small (less than 15 nm in diameter), well-defined in shape and crystalline, and were characterised before and after electrochemical testing also via electron microscopy (EM), powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS).
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http://dx.doi.org/10.1002/anie.201908758 | DOI Listing |
Nano Lett
January 2025
Jiangxi Provincial Key Laboratory of Green Hydrogen and Advanced Catalysis, College of Physics, Communication and Electronics, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang 330022, Jiangxi, China.
studies of the relationship between surface spin configurations and spin-related electrocatalytic reactions are crucial for understanding how magnetic catalysts enhance oxygen evolution reaction (OER) performance under magnetic fields. In this work, 2D FeSe nanosheets with rich surface spin configurations are synthesized via chemical vapor deposition. magnetic force microscopy and Raman spectroscopy reveal that a 200 mT magnetic field eliminates spin-disordered domain walls, forming a spin-ordered single-domain structure, which lowers the OER energy barrier, as confirmed by theoretical calculations.
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry and Chemical Engineering, School of Pharmacy, Jiangsu University, Zhenjiang 212013, P. R. China.
Electrochemical water splitting is a promising method for the generation of "green hydrogen", a renewable and sustainable energy source. However, the complex, multistep synthesis processes, often involving hazardous or expensive chemicals, limit its broader adoption. Herein, a nitrate (NO) anion-intercalated nickel-iron-cerium mixed-metal (oxy)hydroxide heterostructure electrocatalyst is fabricated on nickel foam (NiFeCeOH@NF) via a simple electrodeposition method followed by cyclic voltammetry activation to enhance its surface properties.
View Article and Find Full Text PDFNanoscale
January 2025
Centre for Nano and Soft Matter Sciences (CeNS), Shivanapura, Bengaluru 562162, India.
Bifunctional oxygen electrocatalysis is a pivotal process that underpins a diverse array of sustainable energy technologies, including electrolyzers and fuel cells. Metal selenides have been identified as highly promising candidates for oxygen electrocatalysts with electronic structure engineering that lies at the heart of catalyst design. Two-phase Fe-doped nitrogen carbon (NC)-supported nickel selenides were synthesized using a coordination polymer template.
View Article and Find Full Text PDFDalton Trans
January 2025
School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, P. R. China.
The design of acidic oxygen evolution reaction (OER) electrocatalysts with high activity and durability is the key to achieving efficient hydrogen production. Herein, we report a Cr-doped RuO (RuCrO) catalyst that exhibits good OER activity in acidic electrolytes. The doping of Cr increases the valence state of Ru, which enhances the activity of the catalyst, and a current density of 10 mA cm can be achieved at only 235 mV, which is superior to that of unmodified RuO of 299 mV.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen, 518057, China.
Over-oxidation of surface ruthenium active sites of RuO-based electrocatalysts leads to the formation of soluble high-valent Ru species and subsequent structural collapse of electrocatalysts, which results in their low stability for the acidic oxygen evolution reaction (OER). Herein, a binary RuO/NbO electrocatalyst with abundant and intimate interfaces has been rationally designed and synthesized to enhance its OER activity in acidic electrolyte, delivering a low overpotential of 179 mV at 10 mA cm, a small Tafel slope of 73 mV dec, and a stabilized catalytic durability over a period of 750 h. Extensive experiments have demonstrated that the spillover of active oxygen intermediates from RuO to NbO and the subsequent participation of lattice oxygen of NbO instead of RuO for the acidic OER suppressed the over-oxidation of surface ruthenium species and thereby improved the catalytic stability of the binary electrocatalysts.
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