Preparation Of Alloy Nanoparticle Arrays On ITO And The Characterization Of Electriocatalytic Properties

Chemical and physical properties of nanomaterials are closely dependent on its structure. Electrochemical synthesis methods of nanoparticles have been used to control the structure of nanomaterials by adjusting applied conditions such as the current or voltage signal. With the development of devices to miniaturization, micro/nano processing technology puts forward higher requirements. Micro arrays composed of nanoparticles have been widely used in the research of catalytic properties of nanomaterials. As indium tin oxide (ITO) conductive glass has good quality including transparency of light, electrical conductivity, wide potential window and stable physical and chemical properties, this paper describes the application of the electrochemical wet stamping technology and microcontact printing technology (μCP) to prepare microstructure on the ITO surface. The morphology, composition and the structure were studied and the electrochemical techniques and scanning electrochemical microscopy were applied to study the catalytic properties.1. Au and AuPd arrays were deposited onto an indium tin oxide (ITO) surface by electrochemical wet stamping method. Agarose stamp with microstructures and solution was used to electrodeposit and generate patterns of a certain thickness. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDX) and atomic force microscope (AFM) were employed to characterize the morphology and components on the surface. Tip generation-substrate collection mode (TG-SC) and redox-competition mode (RC) of scanning electrochemical microscopy (SECM) combined with cyclic voltammetry were used to explore the electrocatalytic activity of alloy arrays. In the study of electrocatalysis, AuPd exhibited higher activity for the reduction of H2O2 than pure Au, but lower activity for that of ferrocenemethanol oxide (FcMeOH+).2. On the basis of research for AuPd alloy and Au bicomponent array patterns, we continue to explore multicomponent array patterns. SEM experiment results show that with the increase of the Pd content, the nucleation process of alloy nanoparticles on ITO prepared by electrochemical wet stamping technology, gradually changes from continuous nucleation to instantaneous nucleation. EDX and XRD showed that the composition of nanoparticles is greatly influenced by electrolyte solution, at the same time, XRD proved AuPd nanoparticle belongs to alloy structure. Electrochemical technology combined with scanning electrochemical microscopy is used to screen the optimal composition to improve its catalytic activity.3. Microarray patterns were prepared by microcontact printing technology (μCP). Chemical reduction method was used for synthesis of metal nanoparticles (Au,Pd) and AuPd nanoparticles by controlling reaction conditions such as the ratio of Au and Pd precursor, reaction time and reaction temperature to obtain nanoparticles with different composition, morphology and structure. The prepared nanoparticles were assembled to the surface of PDMS. The nanoparticles on the surface of PDMS stamp were transferred to Hydrophilic ITO by μCP, forming order structures or patterns.