Ni foam supported three-dimensional vertically aligned and networked layered CoO nanosheet/graphene hybrid array as a high-performance oxygen evolution electrode

作者：Yuan, Weiyong^*; Zhao, Ming; Yuan, Jia; Li, Chang Ming

来源：Journal of Power Sources, 2016, 319: 159-167.

DOI：10.1016/j.jpowsour.2016.04.044

• Layered nanostructure
• Nanosheet
• Vertically aligned nanoaray
• Graphene
• Oxygen evolution

The sluggish oxygen evolution reaction (OER) represents a major kinetic bottleneck in water splitting. Herein we report the synthesis of a novel Ni foam (NF) supported 3-D vertically aligned and interconnected layered CoO nanosheet array with controlled density, layer thickness, and interlayer spacing, and the conformal self-assembly of graphene on this nanosheet array. The obtained CoO layered nanosheet/graphene hybrid nanoarray was directly used as an OER electrode, showing a current density of 10 mA cm(-2) at an overpotential of 330 mV and a Tafel slope of 79 mV dec(-1), both of which are much lower than pristine NF and the nanosheet array without graphene, and are among the lowest reported for Co-based OER catalysts and transition metal oxide-based ones measured under the same conditions. In addition, it can retain 92.4% of the current density after 66 h of chronoamperometry testing at a potential of 1.0 V vs. SCE, and 94.3% of the current density at 1.0 V vs. SCE after 200 cyclic voltammetry cycles (0-1.0 V vs. SCE). The excellent catalytic activity and stability toward OER are ascribed to the 3-D NF supported robustly grown networked layered nanosheet array structure and the synergistic effects between CoO layered nanosheets and graphene.

• 出版日期2016-7-1
• 单位西南大学