Cu superstructures fabricated using tree leaves and Cu-MnO2 superstructures for high performance supercapacitors

Copper (Cu) superstructures have been originally synthesized by using natural sapless leaves. A novel hybrid nanoarchitecture, Cu-MnO2 composite, is prepared through facile coating of a thin MnO2 nanofilm onto the highly electronically conductive Cu superstructures. Benefiting from their unique structures, as electrode materials of supercapacitors the composite superstructures have a high specific capacity of 1024 F g(-1) at 1.5 A g(-1) and good capacity retention of around 96% after 2000 electrochemical cycles.