Electrochemical deposition of CeO2 nanocrystals on Co3O4 nanoneedle arrays for efficient oxygen evolution

Abstract In this work, we report an efficient catalyst for oxygen evolution reaction based on CeO2 nanoparticles modified Co3O4 nanoneedle arrays directly grown on copper foam. Cobalt hydroxyl carbonate (CoHC) nanoneedle arrays are grown on Cu foam by a hydrothermal method. Using an electrochemical deposition method, Ce(OH)3 is deposited on the surface of the CoHC nanoneedles, which is converted into CeO2 modified Co3O4 with the same morphology by simple calcination in air. Excellent catalytic performance for the oxygen evolution reaction is observed, featured for the low overpotential of only 334 mV at 10 mA cm−2 in 1 M KOH. The enhanced OER performance is attributed to the variable Ce oxidation number and oxygen vacancy in CeO2. The results demonstrate the positive effect of CeO2 for the oxygen evolution reaction which was largely ignored in previous study.