摘要
以醋酸铜(Cu(Ac)2)和正硅酸乙酯(TEOS)为前驱体,柠檬酸钠(Na_3Cit)为配合剂,在室温下制备出物质的量之比n_(Cu^(2+))∶n_(Cit^(3-)) 为1∶1和1∶2的2种透明稳定的Cu(Ⅱ)-Cit^(3-)-SiO_2复合溶胶。以此为电解液,采用恒电位方法,在ITO阴极上直接制备出了Cu_xO-SiO_2复合薄膜。CV(循环伏安)和XRD(X射线衍射)结果表明,在低过电位和高过电位分别得到Cu2_O-SiO_2和Cu/Cu_2O-SiO_2薄膜。XRD和EDX(X射线散射能谱)结果表明,相同沉积条件下,n_(Cu^(2+))∶n_(Cit^(3-)) 为1∶1溶胶中得到的薄膜中Cu含量较1∶2溶胶中的高。薄膜在2种溶胶中的电化学形成机理不同,其原因在于溶胶中Cu(Ⅱ)存在的形式不同。CA(计时安培)和SEM(扫描电镜)结果一致表明,Cu和Cu_2O在2种溶胶中的成核机理与电位有关,随着过电位增大,成核机理从三维连续成核逐渐转向瞬时成核。
Two stable composite Cu（Ⅱ）-Cit^3--SiO2 sols with molar ratios（ n（Cu^2＋）∶n（Cit^3-） ） of 1∶1 and 1∶2 were prepared at room temperature using copper acetate and tetraethoxy-silane as precursors and sodium citrate as complexing agent, respectively. Using the as-prepared sols as electrolytes, CuxO-SiO2 composite gel films are prepared directly on ITO cathode by potentiostatic electrodeposition method. CV（cyclic voltammetry） and XRD（X-ray diffraction） results indicated that Cu2O-Si O2 and Cu/Cu2O-SiO2 composites gel films were obtained in sols at lower and higher overpotentials, respectively. CV results revealed that the electrochemical formation mechanisms of the composite films were different each other because of different Cu （Ⅱ） complex ions in their respective sols. XRD and EDX（Energy dispersive X-Ray spectroscopy） results indicated that the Cu content of the as-prepared composited films in sol with n（Cu^2＋）∶n（Cit^3-） of 1∶1 are higher than those of as-prepared films in sol with n（Cu^2＋）∶n（Cit^3-） of 1∶2sol. Chronoamperometry（CA） results suggested the nucleation mechanism of Cu2 O and Cu in silica sols changed gradually from 3DP（progressive nucleation with three-dimensional growth） to 3DI（instantaneous nucleation with three-dimensional growth） with the increase of overpotentials, which was confirmed by SEM images.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2016年第4期617-624,共8页
Chinese Journal of Inorganic Chemistry
基金
国家重点基础研究发展规划项目(No.2014CB239204)
CMDDC国家重点实验室自主项目(No.2011DA105287-ZD201202)
重庆市科技计划项目(No.cstc2013jcyjys90001)资助
