Blue TiO2 nanosheets as a high-performance electrode material for supercapacitors

We are reporting the use of blue titanium oxide (b-TiO2) nanostructures as advanced electrode material for high performance supercapacitor for the first time. A one-pot hydrothermal route was employed for the oxidation of layered titanium diboride (TiB2) into b-TiO2 nanosheets. The b-TiO2 nanosheets are prepared via hydrothermal oxidation of TiB2. Physico-chemical characterizations such as X-ray diffraction, UV-visible, photoluminescence spectroscopy, electron spin resonance spectroscopy, laser Raman spectrum, X-ray photoelectron spectroscopy, and morphological studies revealed the formation of sheet-like b-TiO2 nanostructures. The energy storage properties of the b-TiO2 electrode were examined using aqueous and organic electrolytes. The cyclic voltammetry and charge-discharge analysis of b-TiO2 electrode using 1 M Na2SO4 revealed their pseudocapacitive nature with a high specific capacitance (similar to 19 mF cm(-2)). The b-TiO2 based symmetric supercapacitor (SSC) device using organic liquid (1 M TEABF(4)) works over a wide operating potential window (3 V) and delivered a high specific capacitance (6.67 F g(-1) or 3.58 mF cm(-2)), possess high energy density and power density with excellent cyclic stability over 10,000 cycles. Collectively, these studies demonstrated the usefulness of b-TiO2 as a novel electrode material for high performance supercapacitor. (C) 2018 Elsevier Inc. All rights reserved.