Electrochemically Doped and Hydrogen Peroxide–Treated TiO2 Nanotube Arrays as an Electrode for Supercapacitor with Excellent Cycling Stability

Abstract

Ordered anodic TiO2 nanotube arrays hold great potential as electrode materials for high-performance supercapacitors. However, their poor cycle stability restricts practical applications. Here we develop a simple and successful strategy to improve their cycle stability. The TiO2 nanotube arrays are electrochemically doped in a basic solution, followed by soaking them in a hydrogen peroxide solution for a short time. The as-prepared TiO2 nanotube arrays possess a core–shell structure with an amorphous surface layer of 2–3 nm thickness. The supercapacitors made by the as-prepared TiO2 nanotube arrays exhibit an excellent cycling stability with a capacitance retention of 94.1% after 10000 cycles. The presented results make TiO2 an attractive candidate as electrode materials in high-performance supercapacitors.