Spinel NiCo2O4 3-D nanoflowers supported on graphene nanosheets as efficient electrocatalyst for oxygen evolution reaction. (21st June 2019)

• Record Type: Journal Article
• Authors: Li, Zesheng; Li, Bolin; Chen, Jiaming; Pang, Qi; Shen, Peikang
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 31(2019)
• Page Start: 16120
• Page End: 16131
• Publication Date: 2019-06-21
• Subjects: Bimetallic oxides -- NiCo2O4 nanoflowers -- Graphene nanosheets -- Solvothermal synthesis -- Oxygen evolution reaction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.04.219
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Efficient oxygen evolution reaction (OER) electrocatalysts with non-noble metals are very critical for the large-scale exploitation of electrocatalytic hydrogen production systems. To improve the catalytic activity of OER electrocatalysts, several design strategies, such as construction of nanostructures, porous structures and composite materials have been proposed. Herein, spinel NiCo2 O4 3-D nanoflowers supported on graphene nanosheets (GNs) are prepared by a simple solvothermal synthesis method as non-noble metal electrocatalysts for OER. The present NiCo2 O4 /GNs composite integrates multiple advantages of nanostructures, porous structures and composite materials, including high surface area, abundant catalytic sites and high stability. Benefiting from the favorable features, the NiCo2 O4 /GNs composite exhibits a better OER performance than NiCo2 O4 and RuO2 in alkaline medium, which has a low onset potential (1.50 V), a small Tafel slope (137 mV dec −1 ). The present work opens a new window for the construction of the carbon-supported 3-D nanostructure of transition metal catalysts with optimizable electrocatalytic performances for electrocatalytic hydrogen production. Graphical abstract: A composite catalyst of spinel NiCo2 O4 3-D nanoflowers/graphene nanosheets is successfully fabricated as non-noble metal electrocatalyst for oxygen evolution reaction (OER).Image 1 Highlights: 3-D hierarchical structure of NiCo2 O4 nanoflowers are fabricated on graphene nanosheets. A convenient and efficient graphene-mediated solvothermal synthesis strategy is proposed. Hierarchical NiCo2 O4 nanoflowers provide short paths for fast transfer of electrolyte ions. Graphene nanosheet makes up for the defect of poor conductivity of NiCo2 O4 component. The composite exhibits favorable catalytic performance and good stability toward the OER.