Preparation And Electrochemical Properties Of Boron-doped Diamond Films

In this paper, Boron doped diamond films were prepared on P(100) silicon substrates by DC hot cathode CVD system, B(OCH3)3 was the doped chemical. The samples we prepared were characterized by scanning electronic microscope (SEM), X-ray diffractometer (XRD), Raman spectrum microscopy etc. The electrochemical performance of BDD electrodes were tested by electrochemical workstation. The degradation efficiency of nitrobenzene at BDD electrodes was measured. The main work we done showed as follow:1. The influence of B(OCH3)3 flow rate, substrate temperature and gas pressure was studied. It shows that B(OCH3)3 flow rate and substrate temperature were the main factors that effect on the growth of boron doped diamond films.The doped boron atom changed the structure of diamond significantly. As the flow rate of B(OCH3)3 increased, which ranges from 0 to 30 sccm, the lattice constant rises from 0.35665nm to 0.35746nm, the crystal grain surface turned smooth and the Raman spectrum suggests that the quality of diamond films has a trend of descending after ascending. The surface resistivity of BDD films decreased rapidly, and finally gets stable when the flow rate greater than 1sccm, which reaches about 100 ?·cm.Substrate temperature ranges from 750℃to 1050℃, the crystal grain enlarged with the substrate temperature rise up, and the tensile stress was also increased.2. The electrochemical performance of BDD electrode was tested by electrochemical workstation. B(OCH3)3 flow rate effects on the performance of BDD electrode strongly. The electrode has the widest potential window, lowest background current, highest oxygen evolution potential when the B(OCH3)3 flow rate is 1 sccm.3. We chose 36mg/L nitrobenzene solution as the pollutant. The degradation of nitrobenzene on BDD electrode was measured by COD analyzer.