Preparation of Ni Nanoparticles-TiO2 Nanotube Arrays Composite and Its Application for Electrochemical Capacitor

Ni nanoparticles-TiO2 nanotube arrays (Ni/TiO2NTs) composites were prepared by pulsed electrodeposition method and subsequently characterized by means of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The FESEM results showed that highly dispersed Ni nanoparticles were not only loaded on the top of the TiO2NTs but also within the tubular structure, and the particle size of Ni prepared at different current amplitude (100, 200 and 300 mA center dot cm(-2)) was in the range of 15 to 70 nm. The electrochemical studies indicated that Ni nanoparticles loaded on the highly ordered TiO2NTs are readily accessible for electrochemical reactions, which improve the efficiency of the Ni nanoparticles and TiO2NTs. A maximum specific capacitance (27.3 mF center dot cm(-2)) was obtained on the Ni/TiO2NTs composite electrode that prepared at a current of 200 mA center dot cm(-2), and the electrode also exhibited excellent electrochemical stability.