物理化学学报 >> 2012, Vol. 28 >> Issue (08): 1929-1935.doi: 10.3866/PKU.WHXB201205231

电化学和新能源 上一篇    下一篇

水滑石负载的钯纳米粒子对水合肼的电催化氧化

金荣荣, 李丽芳, 徐雪峰, 连英惠, 赵凡   

  1. 山东农业大学化学与材料科学学院, 山东 泰安 271018
  • 收稿日期:2012-02-03 修回日期:2012-05-21 发布日期:2012-07-10
  • 通讯作者: 李丽芳 E-mail:fangll@sdau.edu.cn
  • 基金资助:

    山东省优秀中青年科学家奖励基金(2008bs07016)资助项目

Layered Double Hydroxide Supported Palladium Nanoparticles for Electrocatalytic Oxidation of Hydrazine

JIN Rong-Rong, LI Li-Fang, XU Xue-Feng, LIAN Ying-Hui, ZHAO Fan   

  1. College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shan-dong Province, P. R. China
  • Received:2012-02-03 Revised:2012-05-21 Published:2012-07-10
  • Contact: LI Li-Fang E-mail:fangll@sdau.edu.cn
  • Supported by:

    The project was supported by the Outstanding Young Scientist Research Award Fund of Shandong Province, China (2008bs07016).

摘要:

利用共沉淀方法制备了载体水滑石(LDH), 通过离子交换法将PdCl24- 插入水滑石层间, 再用水合肼将其还原, 制备得到了水滑石负载的分散状钯纳米粒子(LDH-Pd0). 利用X射线衍射(XRD)、透射电镜(TEM)和X射线电子能谱(XPS)等手段对所得样品进行了表征, 结果表明钯纳米粒子能很好地分散在水滑石上. 将该纳米材料修饰的玻碳电极(GCE)用于水合肼的电催化氧化, 该修饰电极表现出很好的电化学催化活性. 用循环伏安法(CV)、计时库仑法(CC)和计时安培法(i-t)对修饰电极的催化活性、有效表面积和水合肼的催化氧化机理等进行了研究. 结果表明水合肼在-0.1 V附近有明显的氧化峰, 在1.0×10-5-2.0×10-4 mol·L-1范围内, 阳极峰电流与水合肼浓度间有良好的线性关系, 其检测限为9.5×10-7 mol·L-1. 计算得到GCE, LDH-Pd0/GCE 和LDH/GCE电极活化面积分别为0.02089, 0.02762 和0.02496 cm2. 推知水合肼的氧化过程有4 电子和4 质子参与, 并且其在电极上的反应是受扩散控制的不可逆过程.

关键词: 水滑石, 钯纳米粒子, 循环伏安, 水合肼, 修饰电极, 电催化

Abstract:

A Mg-Al layered double hydroxide (LDH) was prepared from Mg(NO3)2·6H2O and Al((NO3)3· 9H2O by a constant-pH co-precipitation method at room temperature. PdCl24- was successfully introduced into the gallery space of the Mg-Al-LDH via an ion exchange process, and then reduced by hydrazine to produce LDH-supported palladium (LDH-Pd0) nanomaterials. The sample was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that palladium nanoparticles were well dispersed on the LDH surface. The LDH-Pd0 nanomaterial was immobilized on a glassy carbon electrode (GCE) to oxidize hydrazine in a phosphate buffer solution (PBS, pH 7.0) using cyclic voltammetry (CV). The modified electrode exhibited excellent electrocatalytic activity and thus could be used to determine the concentration of hydrazine. This was verified by examining the amperometric response at a working potential of -0.1 V, where it was found that the anodic peak current of the modified electrodes was linear with hydrazine concentration in the range of 1.0×10-5-2.0×10-4 mol·L-1. The detection limit was 9.5×10-7 mol·L-1 at a signal-to-noise ratio of 3. The electrochemically effective surface areas were determined by chrono-coulometry (CC) to be 0.02089, 0.02762, and 0.02496 cm2 for GCE, LDH-Pd0/GCE, and LDH/GCE, respectively. The irreversible oxidation of hydrazine on the modified electrode is diffusion controlled with the participation of four electrons and four protons.

Key words: Layered double hydroxide, Palladium nanoparticle, Cyclic voltammetry, Hydrazine, Modified electrode, Electrocatalysis

MSC2000: 

  • O646