title: Covalently Coupled Ultrafine H-TiO2 Nanocrystals/Nitrogen-Doped Graphene Hybrid Materials for High-Performance Supercapacitor.
abstract: Hydrogenated TiO2 (H-TiO2) are considered one of the most promising materials for supercapacitors given its low-cost, high conductivity, and enhanced electrochemical activity. However, the electrochemical performances of H-TiO2 due to lacking suitable structures is unsatisfactory, and thus how to design energetic H-TiO2-based electrode architectures still remains a great challenge. Herein, covalently coupled ultrafine H-TiO2 nanocrystals/nitrogen-doped graphene (H-TiO2/NG) hybrid materials were developed through a simple hydrothermal route followed by hydrogenation. Within this architecture, the strong interaction between H-TiO2 nanocrystals and NG sheets via covalent chemical bonding affords high structural stability inhibiting the aggregation of H-TiO2 nanocrystals. Meanwhile, the NG matrices function as an electrical highway and a mechanical backbone so that most of well-dispersed ultrafine H-TiO2 nanocrystals are electrochemically active but stable. As a result, the optimized H-TiO2/NG (H-TiO2/NG-B) exhibited high reversible specific capacity of 385.2 F g(-1) at 1 A g(-1), enhanced rate performance of 320.1 F g(-1) at a high current density of 10 A g(-1), and excellent cycling stability with 98.8% capacity retention.
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Shuhua
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Lian
authors.initials: L
authors.lastname: Gao
keywords: covalent chemical bond; high capacity; hydrogenation; nitrogen-doped graphene; supercapacitor; ultrafine TiO2 nanocrystals