Boron doped diamond electrode and preparation method thereof

Abstract

The invention provides a boron doped diamond electrode. The boron doped diamond electrode comprises an electrode substrate, transition layers and boron doped diamond film layers; the transition layersare arranged on one side or the two sides of the electrode substrate; the boron doped diamond film layers are arranged on the transition layers; the transition layers are made of one or more of titanium diboride, niobium diboride, tantalum diboride and wolfram diboride; and the electrode substrate is made of titanium, niobium, tantalum or wolfram. According to the boron doped diamond electrode, materials such as the titanium diboride are used to form the transition layers between the electrode substrate and boron doped diamond films, so that a loose carbide layer is effectively prevented frombeing formed on the surface of a metal substrate, binding force between the boron doped diamond films and the substrate is increased, and the boron doped diamond films are high in quality, are denseand have no holes; the boron doped diamond electrode is used for treating an anode of high concentrated organic wastewater by an electrochemical advanced oxidation method; the corrosion resistance ishigh; the working life of the electrode is long; and the treatment efficiency is high. The invention further provides a preparation method of the boron doped diamond electrode.

Description

technical field [0001] The invention relates to the technical field of novel functional thin film materials, in particular to a boron-doped diamond electrode and a preparation method thereof. Background technique [0002] In recent years, the boron-doped diamond electrode has the advantages of high electrochemical oxidation potential, stable chemical properties and corrosion resistance, wide potential window and high oxygen evolution potential due to the boron-doped diamond material (BDD) on its surface. The application research in the field of degrading various high-concentration organic wastewater has received extensive attention at home and abroad. [0003] However, despite the excellent chemical stability of boron-doped diamond electrodes, studies have shown that the electrodes will still be corroded in the process of treating organic matter in wastewater under high voltage and high current density conditions, which seriously restricts the wide application of diamond ele...

AI Technical Summary

Problems solved by technology

[0003] However, despite the excellent chemical stability of boron-doped diamond electrodes, studies have shown that the electrodes will still be corroded in the process of treating organic matter in wastewater under high voltage and high current density conditions, which seriously restricts the wide application of diamond electrodes.

Taking the titanium metal substrate as an example, the main cause of electrode corrosion is that during the process of directly depositing BDD films on the titanium substrate, carbon atoms will first react with the titanium substrate to form a thicker titanium carbide (TiC) layer (>50 μm), The titanium carbide layer structure is relatively loose and the surface is rough. Although the diamond film is easy to nucleate and grow on this TiC layer, many holes will be formed at the interface, which will reduce the bonding performance between the film and substrate, thereby affecting the quality of the BDD film and the electrode. Anti-corrosion performance, causing the electrode to become unstable during the electrolytic oxidation process, easily causing film splitting and peeling, and reducing the life of the electrode

Other metals such as niobium, tantalum and other substrates also face the same problem, which greatly limits the industrial application of BDD electrodes for organic wastewater treatment

[0004] In order to solve this problem, some researchers proposed a method to form a passivation layer on the surface of titanium substrate by anodic oxidation technology to suppress the formation of titanium carbide loose transition layer, but the passivation layer formed by this method is high-valent titanium oxide, which will It leads to the increase of the interface resistance and the decrease of the electrochemical performance of the BDD electrode, and the titanium oxide passivation layer is also unstable in the hydrogen plasma environment of diamond deposition

In addition, some researchers proposed to prepare a layer of tantalum-containing intermediate layer on the titanium substrate first, and then deposit the BDD film, but the tantalum metal in the intermediate layer is also a metal that is easily carbided, and tantalum carbide (TaC) will be formed, which cannot effectively prevent the formation of carbon dioxide. Carbonization of source-to-substrate material and formation of a loose transition layer

Therefore, so far, no suitable intermediate layer has been found to improve the interfacial bonding between the metal substrate and the BDD film.

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