摘要
通过铜箔基体上电沉积泡沫铜结合伽尔瓦尼置换反应制备出了银-铜(Ag-Cu)纳米枝晶,利用X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)对枝晶的成分及形貌进行研究发现,随着沉积过电位的增加,铜的前驱体形貌由棒状到枝晶状,最后发展为泡沫状,但泡沫状的前驱体制备的Ag-Cu枝晶却是最规整和致密的.另外,银离子的浓度也会影响枝晶的形貌,一定范围内浓度的增加有利于枝晶的形成.通过线性扫描伏安和电流-时间曲线对制备的Ag-Cu枝晶催化性能进行表征,在电解质溶液中,-0.25V(相对于饱和甘汞电极(SCE))时有一个明显的双氧水(H2O2)还原峰,这意味着Ag-Cu枝晶对H2O2的电还原具有较好的催化活性,当该电极被用于双氧水传感器时,电流响应快,能在3s内达到稳态电流,线性测量范围为0.1-12mmol·L-1,灵敏度可以达到330.36μA·(mmol·L-1)-1·cm-2,这点对于提高传感器的准确性非常重要.
We synthesized silver-copper （Ag-Cu） dendritic structures on Cu foil by electrodeposition and subsequent galvanic displacement reaction. The crystalline nature and morphology of the nanostructures were examined by X-ray diffraction （XRD） and field-emission scanning electron microscopy （FE-SEM）, respectively. The morphology of the Cu precursor changed from rod to dendrite, and finally grew into foam as the overpotential was increased. When the Cu precursor was reacted with silver nitrate through galvanic displacement reaction, a foam-like precursor produced a denser, more uniform Ag-Cu dendrite. In addition, the concentration of silver nitrate solution had a considerable effect on the shape of the nanoparticles, with increasing concentration within a certain range promoting dendrite formation. The electrochemical properties of the Ag-Cu dendrite-modified electrode were characterized by linear sweep voltammetry and amperometric current-time curves. The reduction peak potential was about-0.25 V （vs a saturated calomel electrode （SCE）） in the electrolyte solution, which indicates that the as-synthesized Ag-Cu dendrites have favorable electroreduction activity towards hydrogen peroxide （H202）. When an Ag-Cu dendrite was used as a sensor, the electrode exhibited a rapid response time of 3 s, a wide linear range of 0.1-12 mmol L^-1 H2O2, and a remarkable sensitivity of 330.36 μA, （mmol, L^-1）-1. cm-2, which is particularly important to improve the accuracy of sensors.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2013年第8期1712-1718,共7页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(51271148
50971100)
凝固技术国家重点实验室自主研究课题(30-TP-2009)
航空科学基金(2012ZF53073)资助项目~~
关键词
电沉积
银-铜纳米枝晶
双氧水
电催化
传感器
Electrodeposition
Silver-copper nanodendrite
Hydrogen peroxide
Electro-catalysis
Sensor
