Fabrication and electrochemical capacitance of polyaniline/titanium nitride core–shell nanowire arrays

A novel polyaniline/titanium nitride (PANI/TiN) core–shell nanowire arrays (NWAs) have been fabricated on carbon fibers (CFs) substrate and applied as an electrode material of electrochemical supercapacitor. TiN NWAs were prepared via a seed-assisted hydrothermal process and then ammonia nitridation process. PANI/TiN core–shell NWAs were prepared by electrodepositing PANI onto TiN NWAs. Scanning electron micrographs revealed that TiN NWAs consisted of bundle of small nanowires with a diameter of 10–30 nm and an average length of 1 μm. High-density TiN NWAs offered a high specific surface area for PANI coating layer. Electrochemical measurements showed that a very high specific capacitance of 1064 F g−1 at a current density of 1 A g−1 (based on the mass of PANI) was obtained for PANI/TiN core–shell NWAs. The specific capacitance of PANI/TiN core–shell NWAs could even achieve 787.5 F g−1 at a higher current density of 5 A g−1 and still kept 95% capacity retention after 200 cycles. These results indicated that the PANI/TiN core–shell NWAs showed the promising application as supercapacitor electrode materials for energy storage.