Conductive diamond film for electrode and its preparation method

Abstract

The present invention relates to a conductive diamond film for electrode and its preparation method. It is mainly applicable to electrochemical analysis and detection. Said film contains 0.3%-5% of boron and 99.5%-99.7% of carbon content, and is prepared by adopting microwave reinforced chemical gas phase deposition process. In the course of preparation using silicon as base, making the silicon base undergo the processes of sand-blasting, cleaning, placing in diamond powder and ethyl alcohol mixed solution, ultrasonic wave treatment, and then placing the above-mentioned material in settling chamber, selecting and using hydrogen and methane mixed gas as reaction gas of carbon source, and selecting and using 1% of trimethyl borate and 99% of hydrogen gas mixed gas as boron-doping gas source, sending microwave whose frequency is greater than 2GH2 into the settling chamber so as to make gas being in settling chamber produce plasma. By controlling flow speed of the above-mentioned gas source and growth time the diamond film with required content and thickness can be obtained. Said diamond film can be directly used as electrode.

Description

Technical field: [0001] The invention relates to a conductive diamond thin film used for electrodes and a preparation method thereof, which is mainly used for electrodes in electrochemical analysis and detection, so as to improve test accuracy, repeat accuracy and prolong the service life of electrodes. Background technique: [0002] In the field of chemistry, the method of electrification is often used to test and analyze the chemical composition of liquids and gases. Sometimes these liquids and gases have a strong corrosive effect, which can easily corrode the electrified electrode, resulting in a decrease in measurement accuracy or even damage. We know that diamond has very good chemical stability and mechanical properties, but no matter whether it is natural or synthetic diamond or the diamond film prepared by chemical vapor deposition, it is not conductive (the forbidden band width of diamond is 5.5ev). This limits its application in the electrical field. Recent studie...

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Problems solved by technology

However, this electrode also has some disadvantages: 1. The boron-doped diamond film is easy to fall off from the metal surface, causing damage to the electrode; 2. The metal part not covered by the diamond film will corrode, resulting in a decrease in electrode performance; 3. The boron-doped concentration is low, The thin film has poor electrical conductivity and cannot be used for precise detection;