Facile synthesis of CoFe-LDH/MWCNT/rGO nanocomposite as efficient bifunctional electrocatalysts for oxygen evolution and reduction

摘要

The hydrothermal synthesis of CoFe layered double hydroxide/multiwalled carbon nanotube/reduced graphene oxide (CoFe-LDH/MWCNT/rGO) nanocomposite, a highly efficient bifunctional electrocatalyst for oxygen evolution reaction (OER) and oxygen reduction reactions (ORR), was reported in this work. The hybridization of MWCNT and rGO with CoFe-LDH endows the obtained nanocomposite both hierarchical porous structure and enhanced conductivity, which significantly facilitate the mass transport and charge transfer efficiency for OER and ORR. CoFe-LDH/MWCNT/rGO displayed efficient OER activity in 1.0 M KOH with a low onset overpotential of 330 mV and an overpotential of 430 mV to reach the 10 mA/cm(2) current density. The CoFe-LDH/MWCNT/ rGO also presents excellent ORR catalytic activity with onset potential of 708 mV vs. RHE in 0.1 M KOH with a 4e-route selectivity. The excellent bifunctional catalytic activity of the CoFe-LDH/MWCNT/rGO for OER and ORR could be attributed to the synergistic effects of MWCNT, rGO and CoFe-LDH. (C) 2018 Elsevier B.V. All rights reserved.