CeO2/Co(OH)2 hybrid electrocatalysts for efficient hydrogen and oxygen evolution reaction

Hybrid catalyst has been intensively studied over the past decades due to its advantages in many applications. It has been shown that CeO2 nanoplates with an average diameter of 18.6 nm have uniform contact with Co(OH)(2). The objective of the present study was to comprehensively investigate CeO2/Co(OH)(2) hybrid catalysts using various structural and electrochemical analysis to understand the synergetic effect between CeO2 and Co(OH)(2) beneficial interaction on oxygen evolution and hydrogen evolution reaction (OER and HER) characteristics. OER/HER results showed excellent catalytic activity of CeO2/Co(OH)(2) hybrid catalysts with an overpotential of 410 (OER) and 317 mV (HER) compared to pure CeO2 nanoplates and Co(OH)(2) powder. Corresponding Tafel slopes of CeO2/Co(OH)(2) hybrid catalysts for OER and HER were 66 and 140 mV dec(-1), respectively, lower than those of evaluated CeO2 nanoplates and Co(OH)(2) powder. Compared to bare CeO2 nanoplates and Co(OH)(2), CeO2/Co(OH)(2) hybrid catalysts exhibited remarkably enhanced electrocatalytic activity for OER and HER. (C) 2019 Elsevier B.V. All rights reserved.