Titanium Oxynitride Nanoparticles Anchored on Carbon Nanotubes as Energy Storage Materials

Sub-8 nm titanium oxynitride (TiON) nanoparticles were uniformly formed on the surface of carbon nanotubes (CNTs) by annealing amorphous TiO2 (a-TiO2) conformally coated CNTs (CNTs/a-TiO2) at 600 °C in ammonia gas. The novel CNTs/TiON nanocomposite was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy imaging (HRTEM), scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDX), and X-ray photoelectron spectroscopy (XPS). The results show that Ti, O, and N are homogeneously distributed in TiON nanoparticles. The specific capacitance of CNTs/TiON exhibits 187 F g(-1) at a current density of 0.5 A g(-1), which is much higher than that of CNTs (33.4 F g(-1)) and CNTs/TiO2 (83.4 F g(-1)) obtained by annealing CNTs/a-TiO2 at 450 °C in nitrogen gas. CNTs/TiON also exhibits enhanced cycle durability, which enables it to be considered as a promising candidate for supercapacitors.