石墨电极上电沉积钯镍合金的循环伏安研究

文章编号:1000-2472(2004)02-0005-05

石墨电极上电沉积钯镍合金的循环伏安研究

X

肖耀坤1,苑 娟1,胡波年2,余 刚1X X

,叶立元1

(1.湖南大学化学化工学院,湖南长沙 410082;2.湖南建材高等专科学校,湖南衡阳 421008)

摘 要:用循环伏安法对NiSO 4与PdCl 2混合溶液合成钯镍合金纳米线的电化学沉积条件进行了研究.结果表明,钯镍离子混合液中钯的析出对镍、氢的电极过程有很强的去极化作用,使镍的析出电势正移,减小了钯、镍析出电势的差距.钯离子浓度为2mmol #L -1

,镍

离子浓度为0.32mol #L -1时,有利于形成钯镍合金.高超电势和大电流密度下可以实现钯、镍共沉积.但高浓度和高超电势下,电沉积的电流密度大,使金属的沉积速度过快,不利于形成钯镍合金纳米线.钯镍析出电势相差较大,在低超电势条件下,难于实现共沉积,需通过加入添加剂或络合剂等其它方法来改变钯、镍的析出电势,使二者析出电势更进一步接近以达到共沉积的目的.

关键词:钯镍合金;纳米线;电沉积;循环伏安法

中图分类号:TQ15 文献标识码:A

An Investigation of the Cyclic Voltammetry of Electro -deposition

of Pd -Ni Alloy on Graphite Electrode

XIAO Yao -kun 1,YUAN Juan,HU Bo -nian 2,YU Gang 1**,YE L-i yuan 1

(1.College of Chemistry and Chemical Engineer ing ,Hunan U niv,Changsha,410082;

2.Hunan Colleg e of Building M ater ials,Heng yang,421008)

Abstract:Cyclic Voltammetry (CV)w as used to study the electrochem ical conditions in order to synthesize nanowires of Pd -Ni alloy in the mixtures composed of PdCl 2and N iSO 4.T he results revealed that the palladium deposited from the m ix ture of PdCl 2and NiSO 4could reduce the polarizations of the electrode process of produc -ing Ni and H 2.The depolarization makes the deposit potential of Ni move positively ,w hich reduces the deposit potential difference betw een Pd and Ni.The mixture of 2mmol #L -1PdCl 2and 0.32mol #L -1NiSO 4is favor -able for the formation of the structure of Pd -Ni alloy.Under the condition of large over -potential and high cur -rent density,Pd and Ni can be co -deposited,but under the condition of high ion concentration and large over -po -tential,the high current density causes a fast deposit rate,w hich is disadvantageous to the deposition of the nanowires of Pd -Ni alloy.It is difficult to realize the co -deposition of Pd and Ni at the low over -potential w ith a g reat difference of deposit potentials betw een Pd and Ni.It is necessary to search for other methods,such as af -filiating some complex agents or suitable additives,etc,to change the deposit potentials of Pd and Ni,so as to

make their deposit potentials much closer to each other and to realize the co -deposition of Pd and Ni.

Key words:Pd -Ni alloy;nanow ires;electrochem ical deposition;cyclic voltammetry

X X 通讯联系人:余 刚(1960-),男,湖南郴州人,湖南大学教授. E-mail:yuganghnu@

收稿日期:2003-10-25

基金项目:国家自然科学基金项目资助(20373015);化学生物传感与计量学国家重点室资助项目作者简介:肖耀坤(1965-),男,湖南衡阳人,湖南大学博士研究生.第31卷 第2期2004年4月

湖南大学学报(自然科学版)

Journal of Hunan U niversity (N atural Sciences)Vol.31,No.2Apr 12004