Electronic structure and defect density co-modulation of CoSe₂/CeO₂ nanocomposite for bifunctional hydrogen oxidation and reduction reactions
CoSe₂/CeO₂ 奈米複合材料的電子結構與缺陷密度共調變應用於雙功能氫氧化與氫析出反應
📄 英文摘要
Developing bifunctional non-precious metal electrocatalysts toward hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) in acid is seriously challenged in various applications, such as hydrogen purifiers, fuel cells, and water electrolyzers. Here, we report the development of CoSe₂/CeO₂ nanocomposite electrocatalyst improved by electrochemical tuning for efficient HOR and HER in acid. Electrochemical tuning is shown to generate Ce³⁺, Co³⁺, and oxygen vacancies on the surface of the nanocomposite, which are considered as active sites for the adsorption and desorption of hydrogen species. The tuned catalyst (t-CoSe₂/CeO₂) indicates an impressive activity towards HOR and HER in 0.5 M H₂SO₄ solution, achieving an anodic current density of 1.8 mA cm⁻² at 900 rpm and a cathodic overpotential of 61 mV, respectively, outperforming the commercial Pt/C. Besides, the synthesized electrocatalyst delivers favorable HOR/HER durability. Our results suggest that the surface manipulation of CoSe₂/CeO₂ nanocomposite could provide promising insights for substituting precious electrocatalysts for HOR/HER.
📄 中文摘要
開發能在酸性環境中同時高效驅動氫氧化反應（HOR）和氫析出反應（HER）的雙功能非貴金屬觸媒，對於氯氣純化器、燃料電池和水電解槽等應用至關重要。本研究報告了一種經電化學調變改性的 CoSe₂/CeO₂ 奈米複合材料觸媒，能在酸性環境中有效驅動 HOR 和 HER。研究發現，電化學調變可在奈米複合材料表面產生 Ce³⁺、Co³⁺ 和氧空位，這些作為活性位點，負責氫種物的吸附與脫附。經調變後的觸媒（t-CoSe₂/CeO₂）在 0.5 M H₂SO₄ 溶液中展現優異的 HOR 和 HER 活性：陽極電流密度達 1.8 mA cm⁻²（900 rpm），陰極過電位僅需 61 mV，均超越商用 Pt/C。本研究結果表明，CoSe₂/CeO₂ 奈米複合材料的表面調變工程可為開發替代貴金屬的 HOR/HER 觸媒提供重要參考。
🔬 五項核心重要發現
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