Hydrogenated TiO2@reduced graphene oxide sandwich-like nanosheets for high voltage supercapacitor applications. (January 2018)

• Record Type: Journal Article
• Authors: Pham, Viet Hung; Nguyen-Phan, Thuy-Duong; Tong, Xiao; Rajagopalan, Balasubramaniyan; Chung, Jin Suk; Dickerson, James H.
• Is Part Of: Carbon. Volume 126(2018)
• Page Start: 135
• Page End: 144
• Publication Date: 2018-01
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2017.10.026
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Hydrogenated TiO2 has recently attracted considerable attention as potential electrode materials for supercapacitors due to its abundance, low cost, high conductivity, remarkable rate capability, and outstanding long-term cycling stability. Herein, we demonstrate the synthesis of hydrogenated TiO2 nanoparticles anchored on reduced graphene oxide nanosheets (HTG) in the form of sandwich-like nanosheet composites. Further, we explored their implementation as electrode materials for high voltage, symmetric supercapacitors, operating in the voltage window of 0–1.8 V. The HTGs were prepared by a sol-gel method, followed by hydrogenation in the temperature range 300–500 °C. Of the prepared composites, HTG prepared at 400 °C exhibited the largest specific capacitance of 51 F g −1 at the current density of 1.0 A g −1 and excellent rate capability with 82.5% capacitance retention as the current density increased 40-fold, from 0.5 to 20.0 A g −1 . HTG's excellent rate capability was attributed to its sandwich-like nanostructure, in which ultrasmall hydrogenated TiO2 nanoparticles densely anchored onto both surfaces of the two-dimensional reduced graphene oxide sheets. Moreover, HTG-based supercapacitors also exhibited long-term cycling stability with the retention over 80% of its initial capacitance after 10, 000 cycles. These properties suggest that HTG is a promising electrode material for the scalable manufacture of high-performance supercapacitors. Graphical abstract: Hydrogenated TiO2 has recently attracted considerable attention as potential electrode materials for supercapacitors due to its abundance, low cost, high conductivity, remarkable rate capability, and outstanding long-term cycling stability. In this study, we demonstrate the synthesis of hydrogenated TiO2 nanoparticles anchored on reduced graphene oxide nanosheets (HTG) in the form of sandwich-like nanosheet composites. Further, we explored their implementation as electrode materials for high voltage, symmetric supercapacitors, operating in the voltage window of 0–1.8 V. The HTGs were prepared by a sol-gel method, followed by hydrogenation in the temperature range 300–500 °C. Of the prepared composites, HTG prepared at 400 °C exhibited the largest specific capacitance of 51 F g −1 at the current density of 1.0 A g −1 and excellent rate capability with 82.5% capacitance retention as the current density increased 40-fold, from 0.5 to 20.0 A g −1 . HTG's excellent rate capability was attributed to its sandwich-like nanostructure, in which ultrasmall hydrogenated TiO2 nanoparticles densely anchored onto both surfaces of the two-dimensional reduced graphene oxide sheets. Moreover, HTG-based supercapacitors also exhibited long-term cycling stability with the retention over 80% of its initial capacitance after 10, 000 cycles. These properties suggest that HTG is a promising electrode material for the scalable manufacture of high-performance supercapacitors. Image 1