Ceramic Ti/TiO₂/AuNP Film with 1-D Nanostructures for Selfstanding Supercapacitor Electrodes

Abstract

Herein we have fabricated AuTiO2 from a one-dimensional (1D) nanocomposite by the simple oxidation method of the Ti sheet for supercapacitor applications. We intended on fabricating a microlayer extended into the sheet body to form a selfstanding electrode. Raman spectra and XRD patterns confirmed the formation of the rutile phase of the TiO2 bulk, and FESEM confirmed the growth of the 1D nanostructure made of Au/TiO2, where the Au nanoparticles reside on the tip of the TiO2 nanorods. The growth of 1D TiO2 by this method is supported by a growth mechanism during the oxidation process. Three electrodes were fabricated based on pure and doped TiO2. These electrodes were used as a selfstanding supercapacitor electrode. The Au-doped TiO2 exhibited a great improvement in the electrochemical performance at low Au concentrations, whereas the excessive Au concentration on the TiO2 surface exhibited a negative effect on the capacitance value. The highest areal capacitance of 72 mFcm−2 at a current density of 5 µAcm−2 was recorded for TiO2 doped with a low Au concentration. The mechanism of the electrochemical reaction was proposed based on Nyquist and Bode plots. The obtained results point out that the effect of Au on the TiO2 surface makes Au/TiO2 ceramic electrodes a promising material as selfstanding energy storage electrodes.

Keywords

• 1D nanostructures
• Au-doped TiO₂
• thin-film supercapacitor
• ceramic nanostructures
• standalone nanostructured electrodes