树枝状纳米银颗粒的制备与电活性

Fabrication and electrocatalytic activity of dentrite-like Ag nanoparticles

在Ag(NH3)2+溶液中,在钛基体上电沉积出树枝状纳米银颗粒,研究了沉积电位对树枝状纳米银颗粒形成的影响,探讨了这种树枝状纳米银颗粒形成的机理,并研究了这种钛基树枝状纳米银电极(Ag/Ti)在碱性溶液中对甲醛氧化的电催化活性。结果表明,在30 mmol/LAg(NH3)2+以及沉积电位在-1.8～-1.2 V(vsAg)时,形成了形态为树枝状的纳米银颗粒。在沉积电位为-1.6 V(vs Ag),Ag(NH3)2+浓度为30 mmol/L的溶液中,电沉积制备的这种树枝状纳米银电极(Ag/Ti)对甲醛氧化具有强的电催化活性。循环伏安曲线表明,在0.1 mol/LNaOH溶液中以及甲醛的浓度范围在0～40 mmol/L,甲醛浓度和它的氧化峰电流密度呈现良好的线性关系,检测下限达到0.662 mmol/L,这种新型的树枝状纳米银电极有望作为甲醛检测的传感器。

Dentrite-like Ag nanoparticles were deposited on the Ti substrate by using the electro-deposition process in Ag（NH 3） 2 ＋ solution.Effect of deposition potential on the formation of the dentritic Ag nanoparticles was investigated and the formation mechanism of the dentritic Ag nanoparticles was also discussed.The electrocatalytic activity of the prepared dentrite-like Ag nanoparticles deposited on the Ti（Ag / Ti） towards formaldehyde oxidation in alkaline media was examined.Results showed that dentrite-like Ag nanoparticles were formed in the deposition potential range of-1.8 ～-1.2 V（vs Ag） in the 30 mmol / L-1 Ag（NH 3） 2 ＋ solution.The Ag / Ti electrode,prepared at the deposition potential of-1.6 V（vs Ag）,exhibited high electroactivity for the formaldehyde oxidation.Cyclic voltammetric responses of the Ag / Ti electrode in 0.1 mol.L NaOH containing formaldehyde showed a linear relationship of the oxidation peak current density with the formaldehyde concentration in the formaldehyde concentration range of 0 ～ 40 mmol / L with a formaldehyde detection limit of 0.662 mmol / L,showing a promising application of the novel dentrite-like Ag nanoparticles to the electrochemical sensor of formaldehyde.