Metal Dicyanamides as Efficient and Robust Water Oxidation Catalysts

Non-oxide cobalt based water oxidation electrocatalysts have received attention recently for their relative ease in preparation since they are easy to prepare, stable both in acidic & basic media, and they have higher turnover frequencies compared to cobalt oxides. Recent studies show that one of the main bottlenecks in implementing non-oxide systems to water splitting is the low number of active metal sites, which is in the order of nmol.cm−2. Herein a new series of non-oxide water oxidation catalysts have been introduced to the field. Cobalt dicyanamides are observed to have around four times higher surface active sites and better catalytic performances than cyanide based systems. Long term catalytic studies (70 h) at an applied potential of 1.2 V and electrochemical studies performed in solutions in pHs ranging from 3.0 to 12.0 indicate that the compounds are robust and retain their structures even under drastic conditions. Moreover, addition of nickel impurities to cobalt dicyanamides has been introduced as a feasible method to improve their catalytic activities.