Highly stable supercapacitive performance of one-dimensional (1D) brookite TiO2 nanoneedles. Issue 67 (29th June 2016)

• Record Type: Journal Article
• Authors: Devan, Rupesh S.; Ma, Yuan-Ron; Patil, Ranjit A.; Lukas, Schmidt-Mende
• Is Part Of: RSC advances. Volume 6:Issue 67(2016)
• Page Start: 62218
• Page End: 62225
• Publication Date: 2016-06-29
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra11348f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Conical shaped 1D β-TiO2 nanoneedles tapered in downward direction (left panel) delivered high columbic efficiency (98%) & excellent long-term stability with only 11.8% reduction of C s after 10 000 cycles (right panel) in the electrolyte of Na + ions. Abstract : We report the highly stable supercapacitive performance of one-dimensional (1D) nanoneedles of brookite (β) TiO2 synthesized on a conducting glass substrate. The 1D β-TiO2 nanoneedles synthesized over a large area array utilizing hot-filament metal vapor deposition (HFMVD) were ∼24–26 nm wide, ∼650 nm long and tapered in a downward direction. X-ray photoemission spectroscopy (XPS) revealed their chemical properties and stoichiometric Ti and O composition. The 1D β-TiO2 nanoneedles execute as parallel units for charge storage, yielding a specific capacitance of 34.1 mF g −1 . Electrochemical impedance spectroscopy revealed that the large surface area and brookite crystalline nature of the 1D nanoneedles provided easy access to Na + ions, and resulted in low diffusion resistance, playing a key role in their stable charging–discharging electrochemical mechanism. Moreover, the non-faradic mechanism of these nanoneedles delivered better durability and high stability up to 10 000 cycles, and a columbic efficiency of 98%. Therefore, 1D β-TiO2 nanoneedles hold potential as an electrode material for highly stable supercapacitive performance with long cycle lifetime.