Mesoporous 3D ZnO–NiO architectures for high-performance supercapacitor electrode materials†
Abstract
3D ZnO–NiO mesoporous architectures were synthesized through annealing the zinc hydroxide carbonate–nickel hydroxide carbonate composite precursor, which was prepared via a one-pot hydrothermal route. More importantly, we successfully explore the application of the 3D ZnO–NiO composite mesoporous architectures as electrochemical capacitors. Electrochemical study presented that the as-prepared 3D ZnO–NiO composites under different annealing conditions have different electrochemical supercapacitor properties. The as-synthesized sample obtained at 400 °C shows a high specific capacitance of 2498 F g−1 at a current density of 2.6 A g−1, a good rate capability at high current densities and an excellent long-term cycling stability (about 3.0% loss of the maximum specific capacitance after 2000 cycles), which are mainly attributed to its morphological characteristics of mesoporous and nanosheet self-assembling architectures, as well as a rational composition of the two constituents. These results suggest that such 3D ZnO–NiO mesoporous architectures are promising materials for supercapacitors.