The Preparation Of Pt And Cu₂O Nano Films And Their Catalytic Property Analysis

In this thesis, the Pt nano-film on porous silicon (PS) and Cu2O nano-film on indium-tin oxide (ITO) were prepared by electrochemical techniques. The morphologies of films were characterized with Atomic Force Microscopy (AFM) and Scanning electron microscopy (SEM), while its compositions were analyzed by X-ray diffraction (XRD) and X-ray analysis (EDX). The catalysis properties of films and mechanism of deposition were investigated by electrochemical technologies, such as Cyclic Voltammeter (CV), Open Circuit Potential (OCP), Amperometric i～t, A.C. Impedance (IMP). The promising application in electrochemical catalysis was discussed. The main issues of this thesis were described as follows:1. Ag, Au, Pd, and Pt seed layers were prepared by immersion deposition onto p-Si(100) wafers from noble metal-salt solution containing HF. Atomic force microscope (AFM), Open circuit potential with time (OCP) and A.C. Impedance were used to characterize the morphology and electrochemical property of seed layers. Results showed that during 60 s immersion deposition, the substrate was covered completely by the Ag, Pd and Au; while for Pt, the seed layer was very sparse. Hence, the conclusion was that Ag, Pd and Au could be used as seed layers by immersion deposition on p-Si, but Pt was not proper. The use of seed layers should accord to actual situation.2. Pt nano film had been successfully prepared on Porous silicon (PS) by immersion deposition. The component and morphological properties of the films have been investigated by means of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), which shows that the Pt particles have small size and big specific surface. Cyclic voltammetry (CV) research showed that the Pt nanoparticles had novel catalytic activity for methanol when the immersion deposition time was past 24 min. 3. Pure p-type cuprous oxide thin films have been produced by potentiostatic electrodeposition form Cu( II)—citrate solutions. The morphology and component of the layer can be controlled by deposition potential and pH value, which were studied using Cyclic voltammetry (CV), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Photochemical property was also studied by open circuit potential-time (Ocp-T). The catalysis has good photoelectric effect. Possible deposition and catalysis mechanism have been proposed on the basis of the experimental results.