After many rounds of improvements, the DSA electrode used in sewage treatment often uses titanium plate as the substrate, and the middle layer uses a metal oxide coating with good conductivity and adhesion. For DSA electrodes, the outermost catalytic coating is very important. In sewage treatment, metal elements with high oxygen evolution potential are generally selected as much as possible, and the catalytic coating applied should be dense enough to prevent the oxygen produced by the side reaction from penetrating the coating and oxidizing the base layer, leading to problems such as anode passivation and coating shedding.
It is worth noting that the most commonly used DSA electrode is the ruthenium-iridium electrode, and a small part also contains tantalum and tin, which belongs to the chlorine evolution electrode. The most important element is ruthenium. If sodium persulfate is prepared in a sulfate-based solution, an oxygen evolution electrode should be used. The biggest difference between the oxygen evolution electrode and the chlorine evolution electrode is that the former does not contain ruthenium.
Although the DSA electrode is excellent enough, it is not without shortcomings. Its biggest shortcoming is the life problem, because until now, when preparing DSA electrodes by thermal decomposition, they must be heated at high temperature first and then annealed. The purpose of doing this was originally to enhance the solid solution between different oxide components in the coating and the bonding force between oxide particles. However, this also brings considerable side effects. The most obvious one is that the oxide coating that was burned on with great difficulty cracks due to solvent volatilization and cold-induced shrinkage.
The full name of BDD electrode in Chinese is boron-doped diamond film electrode. Diamond (actually C) has good catalytic properties, making it a potential electrode material.
However, pure diamond is an insulator and does not conduct electricity. In order to overcome this shortcoming, people tried to add boron atoms to it to obtain boron-doped diamond, which can effectively improve the conductivity of diamond, so there was the later BDD electrode technology.
Compared with DSA electrode, BDD electrode has better chemical stability and higher oxygen evolution potential, and its electrochemical window is wider, which can effectively decompose more types of organic pollutants. Therefore, in terms of treatment effect, BDD electrode does have great potential in sewage treatment.
Compared with traditional ruthenium-iridium electrode, BDD electrode is still much more expensive.
Why doesn't BDD electrode use titanium? After all, compared with silicon and niobium, titanium is still relatively cheap.
This is not unheard of. It is mainly because titanium carbide is easily produced when the BDD thin film coating is fired on titanium substrate, and titanium carbide will greatly affect the adhesion between the coating and the substrate, resulting in a short plate life.
Of course, because the catalytic activity of the BDD electrode is better than that of the ruthenium-iridium electrode, its utilization efficiency of current is higher than that of the ruthenium-iridium electrode, which means that when treating the same amount of water, the amount of BDD electrode can be less than that of the ruthenium-iridium electrode.
Over the years, we have been specialized in anode research and development, production and manufacturing, and our products are exported to many countries around the world. Various series of anodes can be designed and produced according to the actual environmental parameters of different users. You are welcome to visit and negotiate.
Nicole
Company: Baoji Jimiyun Dynamic Co., Ltd
Country:China
Add:Baoti road,Jintai,Baoji city,Shaanxi,China
Cel:+86 13369210920
Gmail:nicole@jmyunti.com
Website:www.jm-titanium.com
