NiO nanoparticles decorated hexagonal Nickel-based metal-organic framework: Self-template synthesis and its application in electrochemical energy storage

A one-pot solvothermal strategy and subsequent calcination were proposed for fabricating a composite of NiO nanoparticles on hexagonal Ni-based metal-organic framework (Ni-MOF) (Ni-MOF@NiO). The prepared NiO nanoparticles on the hexagonal Ni-MOF not only improves the electrical conductivity and increases redox active sites, but also prevents the agglomeration of NiO nanoparticles. In particular, highly dispersed and small-sized NiO nanoparticles on the hexagonal Ni-MOF facilitates the migration of electrolyte ions, and the pseudocapacitive performance is evaluated through electrochemical measurements. At 0.5 A g(-1), the Ni-MOF@NiO composite shows a specific capacitance of up to 1192.7 F g(-1) and a high capacity retention (93.23% over 5000 cycles) in 3 M KOH. Moreover, the Ni-MOF@NiO nanoparticles and activated carbon are assembled into aqueous devices with a maximum energy density of 62.2 Wh kg(-1). These results indicate the potential of Ni-MOF@NiO composite as an electrode material for application in supercapacitors. Additionally, the method of synthesizing Ni-MOF@NiO in this study can be used to synthesize other MOF@metal oxide materials for electrochemical energy storage and other related applications. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

A one-pot solvothermal strategy was used to fabricate a NiO nanoparticles on hexagonal Ni-based metal-organic framework (Ni-MOF), showing potential as an electrode material for supercapacitors. The composite exhibited improved electrical conductivity, enhanced redox active sites, prevention of agglomeration, and high specific capacitance with excellent capacity retention over 5000 cycles in 3 M KOH.