Leitfähige Diamantschichten als neues Elektrodenmaterial für die Elektrochemie

Laboratory tests with model systems and the testing in pilot systems under application-oriented conditions have demonstrated the extreme stability and the highest known overpotential for water electrolysis for conductive diamond /1, 2/. Conductive diamond is based on activated low-pressure chemical vapour deposition of boron doped polycrystalline diamond coatings on electrode substrates. The substrate materials are predominantly niobium, titanium or silicon, respectively. The diamond coating technology is able to produce three dimensional electrodes as well as elecrodes with dimensions up to 50 cm x 100 cm /3/. Fundamental investigations have demonstrated an effective anodic oxidation of organic and inorganic (e.g. cyanides) substances in water. This high effectivity is caused by the generation of OH radicals with high current efficiency /4/. The current efficiency for generation of OH radicals on the other hand is based on the high overpotential which suppresses or even avoids the competing generation of oxygen. In this contribution we demonstrate the performance of conductive diamond resulting from these specific properties by application examples in the field of wastewater treatment. Current research and development with the aim of establishing the new electrode material is focusing on quality control for the production of diamond electrodes, development and integration of reactors with diamond electrodes into industrial processes and the investigation of new appliations. This work is performed in close co-operation with industry and research organisations.