Oxygen evolution reaction electrocatalyst based on grafted cobalt and nickel doped carbon dots

• CoNi-CDs are synthesized via hydrothermal microwave method. • CoNi-CDs are diazotized and electro-grafted onto carbon surfaces. • Electro-grafting generates an ordered pattern distribution. • High oxygen evolution reaction (OER) electrocatalytic activity in a basic medium. • Electro-grafting significantly enhances OER electrocatalyst activity. Cobalt and nickel co-doped carbon dots (CoNi-CDs) have been synthesized using hydrothermal microwave assisted methodology. CoNi-CDs have been characterized, showing their ability to be diazotized and electro-grafted onto carbon surfaces, generating an ordered pattern distribution over carbon electrode surfaces. High electrocatalytic activity through oxygen evolution reaction (OER) in basic medium has been proved, showing that the electrocatalyst activity is enhanced when the CoNi-CDs are grafted onto the working electrode instead of just drop-casted. Grafted CoNi-CDs over carbon screen printed electrodes (grafted CoNi-CDs/CSPE) present lower overpotential for OER compared with RuO 2 reference material drop-casted over CSPE. Furthermore, the high turnover frequency of the electrocatalytic centers (cobalt and nickel ions) embedded into the carbon nanostructure enhances the OER electrocatalysis using a small amount of metal for the preparation of the electrocatalyst. In addition, good stability is shown for the modified electrodes used during OER electrocatalyst.