树枝状银纳米颗粒的电沉积法制备及其对葡萄糖的电催化氧化研究

Electrodeposition Synthesis of Dentrite-like Ag Nanoparticles for Electrocatalytic Oxidation of Glucose

在无支持电解质的Ag(NH3)2+溶液中,采用电沉积法在Ti基体上制备出树枝状纳米银电极(Ag/Ti),研究了Ag(NH3)2+浓度改变对纳米银颗粒形貌的影响。结果表明,Ag(NH3)2+浓度为30mmol·L-1时制备的纳米银电极(Ag/Ti-3)呈形状较为规整的树枝状。研究了该树枝状Ag/Ti-3在碱性溶液中对葡萄糖氧化的电催化活性。循环伏安结果表明,在0.1mol·L-1 NaOH溶液中,葡萄糖在Ag/Ti-3电极上的起始氧化电位相对于多晶银电极提前约390mV;0.05V时的恒电位阶跃研究表明,葡萄糖浓度和它的稳态氧化电流密度呈良好的线性关系,检测灵敏度为0.57mA.cm-2(mmol·L-1)-1,检测限13.94μmol·L-1。这种树枝状Ag/Ti-3对葡萄糖检测具有的高灵敏度和较好的选择性,有望作为电化学传感器检测低浓度葡萄糖。

Dentrite-like Ag nanoparticles were deposited on the Ti substrate（Ag/Ti） by using the electrodeposition process in a Ag（NH3）~＋ solution in the absence of supporting electrolyte. The effect of Ag（NH3）＋ concentration on the dentritic structure of Ag nanoparticles was investigated. Results showed that the more regular dendritic shape of silver nanoparticles（Ag/Ti 3） was formed in 30 mmolo L-1 Ag（NH3）＋ solution. Electrocatalytic activity of the Ag/Ti-3 electrode for glucose oxidation was studied in alkaline solution. Cyclic voltammetric data showed that in 0. 1 mol· L-1 NaOH solution, the onset potential of glucose oxidation on the Ag/Ti 3 electrode presented a positive shift of ca. 390 mV compared to that on the polycrystalline Ag electrode. Chronoamperometric responses showed a linear relationship between the stable oxidation current density at 600 s and the glucose concentration,leading to the glucose detection sensitivity of 0.57 mA.cm-2. （mmol-L-1）-1 and detection limit of 13.94 ·mol- L-1. The Ag/Ti 3 electrode also exhibited high selectivity for glucose detection. This dendrite-like silver electrode is a promising electrochemical sensor for the detection of glucose.