Dopamine-modified cobalt spinel nanoparticles as an active catalyst for the acidic oxygen evolution reaction.

The development of efficient non-noble metal electrocatalysts for the oxygen evolution reaction (OER) under acidic conditions remains a critical challenge. Herein, we report a N-doped carbonaceous component-engineered Co 3 O 4 (NCEC) catalyst synthesized via the sol-gel method. Dopamine hydrochloride (DA)-derived nitrogen-doped carbonaceous components were found to boost the OER performance of Co 3 O 4 . The optimized catalyst can reach an overpotential as low as 330 mV in 1 M H 2 SO 4 at a current density of 10 mA cm -2 and maintains a good long-term stability of 60 hours. In particular, we found that the thermodynamic overpotential was inversely proportional to the content of oxidized N and pyridinic N, whereas it was directly proportional to the pyrrolic-N content. Our experiments and density functional theory (DFT) calculations confirm that the optimized catalyst exhibits enhanced charge transfer and the oxidized N species on Co 3 O 4 is responsible for the high catalytic activity. Our study suggests that the performance of NCEC in acidic media can be further optimized by enhancing the content of oxidized N species.