Preparation And Electrochemical Research Properties Of Boron-doped Diamond Thin Film

Diamond has many outstanding characters with physics and chemistry. Preparation of diamond film is extensive went to low temperature low pressure manufacturing technique, compared with the preparation technology of high temperature and high pressure, the process cuts down its difficulty and cost largely and can preparation the bulky tracts of thin film. Born doping gives the film electroconductibility, extensively applying to the field of electrochemistry, electron and photology. Boron-doped diamond thin film with wide potential window, low background current, high chemical stability becomes one of the best electrode materials in the electrochemistry realm. On this basis we can modify the BDD electrode with chemical material. The overpotential of BDD electrode after chemical modification can be effectively lessened, and the transfer rate of electron can be sped, beyond that the electrochemical property between the outside of electrode and the liquid under test is effectively ameliorated. This paper mainly considers three aspects:(1) Preparing the film with boron on the substrate of silicon wafer with direct current plasma jet chemical vapor deposition(DCPJ CVD): preproces the facility and silicon wafer before fabricating the film with solid boron source. On the basis of the theory of plasma jet diamond film equipment through commanding the pressure of the reacted room, temperature, percentage of gases and germinate time, germinate BDD on underlayment.(2) Using SEM、XRD and Raman characterizing boron-doped diamond film : watching film growth is good with(111) as the prime orientation. With the determination of boron-doped film resistivity by hall tester, BDD significantly lower resistivity reaching to 2.81 x 10-4 cm. Detecting the boron-doped diamond thin film to survey its electrochemical features: under the three electrodes system with BDD as the work electrode the result of determining BDD electrode is that its potential window is so broad and background current is close to zero in KCL liquor with 0.1 mol/L.(3) Study the BDD electrode electrochemical testing: There is a pair of good REDOX peak from the voltammetric curves through checking norepinephrine with bare electrode, and the current of peak was in the linear relevance with the detecting rate. Use three substances to chemical modify BDD electrode. Compare electrochemical characters with three sort of modified electrodes and bare electrode in the same conditions of VB6, and then choose the modified electrode which has the strongest electric catalytic oxidation capacity as detection electrodes to test the VB6. The result of the detection is that current with the maximum of oxidation wave and the concentration’s logarithm of VB6 within the scope of 1.0 x10-10- 1.0 x 10-4 mol/L had a good linear relationship, and the detection limit of 1.0 x 10-11 mol/L.