Abstract

Direct methanol fuel cell is claiming to be the most main power source in future as a clean energy source, for which methanol is used as fuel. In the present study, nickel nanoparticles were synthesized by green route in the presence of montmorillonite (Ni-MMT). Then the electrochemical activity of prepared nanocomposite was investigated in methanol oxidation reaction in acidic medium. In the process of nickel nanoparticle synthesis, the natural substrate montmorillonite was used as capping agent and Allium jesdianum water extract was used as the source of reducing agent for the first time. The Ni-MMT sample was characterized by UV–Vis, XRD, SEM and EDX techniques. Production of nickel nanoparticles in the proposed green method is confirmed by absorption peak of 405 nm in UV–Vis spectrum. The average particle size of Ni-MMT was determined as 20.80 nm. The oxidation of methanol in acidic medium was studied by cyclic voltammetry using Ni-MMT-modified carbon paste electrode (Ni-MMT/CPE). Methanol was oxidized on the modified electrode surface at 0.3 V. Also, the catalytic current of methanol oxidation was 3 mA in H₂SO₄ electrolyte which is significantly more than unmodified CPE. The concentration of 0.5 M for H₂SO₄ was obtained as the optimum electrolyte for the oxidation of methanol. Methanol can be catalyzed in the concentration range of 0.1–0.5 M by the prepared nanostructured catalyst.

Graphic abstract

Ni nanoparticles in montmorillonite (Ni-MMT) which was prepared by Allium jesdianum extract have a good electrocatalytic effect on methanol oxidation.

中文翻译：

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Ni-蒙脱土/ Vulcan XC-72R炭黑纳米催化剂在酸性介质中氧化甲醇的电化学活性

摘要

作为清洁能源，直接甲醇燃料电池被宣称是未来最主要的动力，甲醇被用作燃料。在本研究中，在蒙脱石（Ni-MMT）存在下通过绿色途径合成了镍纳米粒子。然后研究了制备的纳米复合材料在酸性介质中甲醇氧化反应中的电化学活性。在镍纳米粒子的合成过程中，天然蒙脱土被用作封端剂，而大葱水提取物首次用作还原剂的来源。Ni-MMT样品通过UV-Vis，XRD，SEM和EDX技术表征。拟议的绿色方法中镍纳米颗粒的生产通过UV-Vis光谱中405 nm的吸收峰得以证实。Ni-MMT的平均粒径确定为20.80nm。使用Ni-MMT修饰的碳糊电极（Ni-MMT / CPE），通过循环伏安法研究了酸性介质中甲醇的氧化。甲醇在0.3 V的修饰电极表面上被氧化。此外，在H ₂ SO ₄电解质中，甲醇氧化的催化电流为3 mA，这明显大于未修饰的CPE。H ₂ SO ₄的浓度为0.5 M获得了作为甲醇氧化最佳电解质的产物。制备的纳米结构催化剂可以在0.1–0.5 M的浓度范围内催化甲醇。

图形摘要

麻葱提取物制备的蒙脱土中的镍纳米粒子（Ni-MMT）对甲醇氧化具有良好的电催化作用。