Hierarchical TiN@Ni(OH)2 core/shell nanowire arrays for supercapacitor application

The TiN nanowire arrays (TiN NWAs) were prepared by hydrothermal treatment of Ti foil and subsequent nitridation through ammonia annealing, on which Ni(OH)2 was electrodeposited to form hierarchical TiN@Ni(OH)2 core/shell nanowire arrays (TiN@Ni(OH)2 NWAs). The electrochemical behaviors of TiN@Ni(OH)2 NWAs were measured by cyclic voltammetry (CV) and galvanostatic charge-discharge, which shows very high specific capacitance (2680 F g−1 at 6 A g−1 in 2 M KOH aqueous solution) and good rate capability (54% capacity retention at 60 A g−1). These results demonstrate that the TiN@Ni(OH)2 NWAs nanostructure is very promising for high performance supercapacitors.