Hierarchical nickel-cobalt phosphide hollow spheres embedded in P-doped reduced graphene oxide towards superior electrochemistry activity

By Tao Dong, Xiao Zhang, Peng Wang, Hsueh‐Shih Chen, Ping Yang. Carbon, 2019

138 citations recorded by the source corpus.

Abstract Hierarchical bimetallic Ni-Co phosphides hollow spheres were encapsulated in P-doped reduced graphene oxide (PrGO) to provide superior electrochemistry performances. The hollow spheres with controlling Co/Ni ratios were obtained via a hydrothermal process and following phosphorization reaction using Ni-Co based glycerate microsphere as a self-sacrificing template. The hollow shell with vertical branches was formed via a morphology evolution of solid, yolk-shell to hollow. The hollow spheres were encapsulated in PrGO networks by a hydrothermal synthesis and phosphorization process to fabricate PrGO/Ni-Co phosphide composite (PrGO/NiCoP). Because of unique morphology and composition, the composite with a Ni/Co molar ratio of 1:1 exhibits enhanced supercapacitor and electrocatalysis properties. As a supercapacitor electrode, PrGO/NiCoP provides high discharge specific capacity, excellent rate performance and cycle stability. An asymmetric supercapacitor assembled with PrGO/NiCoP and activated carbon possesses an energy density of 49.7 Wh/Kg with power density of 0.366 kW/kg, which can successfully illuminate red-light light emitting diode. As an electrocatalyst, PrGO/NiCoP exhibits high hydrogen and oxygen evolution reaction activities in 1 M KOH electrolyte. PrGO/NiCoP electrolyzer shows excellent overall water splitting performance and durability, which required a cell voltage of 1.56 V to achieve a current density of 10 mA cm−2.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/6fa851eada69c50cd205138fe7f72e35db133ce0