Department of Chemistry, University of Farhangian, Tehran, 11369, Iran.
Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
Mikrochim Acta. 2019 May 22;186(6):369. doi: 10.1007/s00604-019-3481-y.
The study presents the synthesis of polypyrrole-coated palladium platinum/nitrogen-doped reduced graphene oxide nanocomposites (PdPt-PPy/N-rGO NC) via direct the reduction of Pd(II) and Pt(II) in the presence of pyrrole monomer, N-rGO and L-cysteine as the reducing agent. X-ray diffraction confirmed the presence of metallic Pd and Pt from the reduction of Pd and Pt cations. Transmission electron microscopy images revealed the presence of Pd, Pt and PPy deposition on N-rGO. Impedance spectroscopy results gave a decreased charge transfer resistance due to the presence of N-rGO. The nanocomposites were synthesized with different Pd/Pt ratios (2:1, 1:1 and 1:2). A glassy carbon electrode (GCE) modified with the nanocomposite showed enhanced electrochemical sensing capability for formaldehyde in 0.1 M sulfuric acid solution. Cyclic voltammetry showed an increase in the formaldehyde oxidation peak current at the GCE modified with PdPt PPy N-rGO. At a typical potential of 0.45 V (vs. SCE), the sensitivity in the linear segment was 345.8 μA.mM . cm. The voltammetric response was linear between 0.01 and 0.9 mM formaldehyde concentration range, with a 27 µM detection limit (at S/N = 3). Graphical abstract Schematic presentation of formaldehyde detection by PdPt-PPy/nitrogen-doped reduced Graphene Oxide Nanocomposite (PdPt-PPy /N-Gr NC). The decrease of charge transfer resistance and the agglomeration of deposited metals in the presence of N-rGO enhance the current response of the electrochemical sensor.
研究提出了通过在吡咯单体、N-rGO 和 L-半胱氨酸存在下直接还原 Pd(II) 和 Pt(II)，合成聚吡咯包覆的钯铂/氮掺杂还原氧化石墨烯纳米复合材料（PdPt-PPy/N-rGO NC）。X 射线衍射证实了 Pd 和 Pt 阳离子还原的金属 Pd 和 Pt 的存在。透射电子显微镜图像显示了 N-rGO 上 Pd、Pt 和 PPy 沉积的存在。阻抗谱结果表明由于 N-rGO 的存在，电荷转移电阻降低。纳米复合材料是用不同的 Pd/Pt 比（2:1、1:1 和 1:2）合成的。用纳米复合材料修饰的玻碳电极（GCE）对 0.1 M 硫酸溶液中的甲醛表现出增强的电化学传感能力。循环伏安法显示在 GCE 上修饰的 PdPt-PPy/N-rGO 上甲醛氧化峰电流增加。在典型的 0.45 V（相对于 SCE）电位下，线性段的灵敏度为 345.8 μA.mM. cm。在 0.01 至 0.9 mM 甲醛浓度范围内，伏安响应呈线性关系，检测限为 27 µM（在 S/N=3 时）。示意图表示通过 PdPt-PPy/氮掺杂还原氧化石墨烯纳米复合材料（PdPt-PPy/N-Gr NC）检测甲醛。在 N-rGO 的存在下，电荷转移电阻的降低和沉积金属的团聚增强了电化学传感器的电流响应。
