Controllable synthesis of CaTi_2O_4(OH)_2 nanoflakes by a facile template-free process and its properties

摘要

Serrated leaf-like CaTi_2O_4(OH)_2 nanoflake crystals were synthesized via a template-free and surfactant-free hydrothermal process. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The growth process for CaTi_2O_4(OH)_2 nanoflakes was dominated by a crystallization-dissolution-recrystallization growth mechanism. BET analysis showed that CaTi_2O_4(OH)_2 nanoflakes had mesoporous structure with an average pore size of 8.7 nm, and a large surface area of 88.4m~2g~(-1). Cyclic voltammetry and galvanostatic charge-discharge tests revealed that the electrode synthesized from CaTi_2O_4(OH)_2 nanoflakes reached specific capacitances of 162 F g~(-1) at the discharge current of 2 mA cm~(-2), and also exhibited excellent electrochemical stability.