An effective graphene confined strategy to construct active edge sites-enriched nanosheets with enhanced oxygen evolution

The sluggish kinetics process derived from oxygen evolution reaction (OER), as the crucial half-reaction, is one of key and bottleneck issues for achieving high-efficiency electrochemical water splitting. Herein, we present a thermally exfoliated graphene (TEG) confined strategy to construct active edge sites-enriched layered double hydroxides (LDHs) nanosheets for OER. The TEG as spatially confined skeleton that features large specific surface area and open frameworks with hierarchical interspace structure, is capable of resulting in effectively confined and dispersed growth of the CoFe-LDH nanosheets. This also finally endows the as-made CoFe-LDH/TEG architectures with the maximized exposure of the edge sites, open and interconnected conducting networks, together with intimate interaction between LDH nanosheets and conductive TEG substrate. These unique and superior characteristics guarantee that the as-made CoFe-LDH/TEG architectures enable the capability of intensifying the reaction process, such as fast electrolyte ion and electron transfer, finally delivering an enhanced electrocatalytic activity and reaction kinetics. (C) 2017 Elsevier Ltd. All rights reserved.