Simple and Effective Way to Improve the Stability of Titanium Based Boron Doped Diamond Film Electrode
- PDF / 783,669 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 29 Downloads / 182 Views
0956-J15-05
Simple and Effective Way to Improve the Stability of Titanium Based Boron Doped Diamond Film Electrode Liang Guo1 and Guohua Chen2 1 School of Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, People's Republic of 2 Department of Chemical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, People's Republic of
ABSTRACT Boron-doped diamond film coated titanium (Ti/BDD) becomes increasingly attractive because of the combined properties of these two unique materials. The challenge for the composite material is the stability especially when it is used as an electrode. In order to meet this challenge, two temperature (2-temp) staged hot filament chemical vapor deposition method was employed in this study. The accelerated working life time was significantly increased to 804 hours for the 2-temp electrode, compared with 244 hours for the diamond film electrode fabricated under one temperature (1-temp) stage method. With the characterization of microRaman, XRD, and cross-sectional SEM, a multilayer of Ti/TiC/(Diamond+Amorphous Carbon)/Diamond can be found in the 2-temp sample and the structure of Ti/TiC/Diamond in the 1-temp sample. There was less void space observed in the interlayer of 2-temp sample. The multi-layered compact structure plays an important role in improving the adhesion of diamond film to the titanium substrate which in turn increases the electrode working life time by over 3 times. INTRODUCTION Ti/BDD electrode has attracted much attention as one of the most ideal electrodes, especially anodes [1-3], in the field of electro-oxidation. The stability of Ti/BDD electrode, however, is a big concern during utilization. Due to the high carbon affinity of Ti, titanium carbide (TiC) was formed prior to diamond deposition. The situation of the TiC interlayer can be influenced by the experimental conditions, especially the substrate temperature. It can be as thick as 150µm [4] or too thin to detect [5], and can be porous or solid. The residual stress in the asgrown diamond film and the TiC interlayer affects the stability of this composite material [6,7]. High residual stress derived from thermal stress and intrinsic stress reduces the adhesion of diamond film to the substrate [6]. Thick and porous TiC interlayer would facilitate the corrosion of this layer leading to the delamination of the diamond film. In this work, Ti/BDD electrode has been fabricated with hot-filament chemical vapor deposition (HFCVD) method. In order to improve the working life time, two temperature stage modified HFCVD method was adopted to manipulate the properties of the interlayers between diamond film and titanium substrate. The working lives of the electrodes were quantified by the accelerated life test and compared. In addition, physical and electrochemical characterization
was performed on the fabricated electrodes to understand the mechanism of the enhancement of the service life. EXPERIMENT 1.1. Diamond Film Dep
Data Loading...
