Key Techniques Of Electrodeposition Metal Silver With Porous Aluminum Oxide Template

With the progress of science and technology, the development of microfabricationtechnology, integration, miniaturization and portability of analytical instrumentation areits growing trend. Detection method which is widely applied is electrochemicaldetection, so its high demands are put forward on the detection electrode. Amicroelectrode which shows many advantageous electrical properties, such as low IR,small time constant, rapid mass transport speed, high current density, improvedsignal-noise-ratio and so on is becoming a hot spot. And the template method andelectrodeposition method are the basic method to fabricate the microelectrode.The article is divided into two parts, one is about the fabrication andcharacterization of anodic aluminium oxide (AAO) template, and another iselectrodeposition metal silver based on AAO template.In the paper, the template is anodic aluminium oxide (AAO) which is prepared by atwo-step aluminum anodic oxidation with0.3M oxalic acid as electrolyte at70Vconstant voltage. AAO is highly ordered nanotube array which has a characteristics ofaverage pore diameter size, controllable pore, high pore density and parallel to eachother. The AAO morphology is confirmed by scanning electron micrograph (SEM).There are three parts in the AAO growth process----forming the barrier layer, formingthe pore hole and further pore growth, which is illustrated by oxidation current and timecurve. Besides, we study technological parameters (annealing, stirring, oxidationvoltage and oxidation time) have the influence on the AAO.Then we apply the potiental to deposite silver with using the AAO template whichis fabricated by a two-step aluminum anodic oxidation before. The electrolyte solutionis composed of AgNO3solution and H3BO3buffer solution. And we have a research onalternating current electrodeposition and direct current electrodeposition respectively. A50Hz ac square wave signal is applied to the alternating current electrodeposition. Thepotential which is applied to the direct current electrodeposition is selected by cyclicvoltammetry. The Ag nanostructures morphology is confirmed by scanning electronmicrograph, and Ag nanostructures are validated by cyclic voltammetry in theelectrochemical workstation.