Hierarchically porous titania xerogel monoliths: synthesis, characterization and electrochemical properties

Hierarchically porous titania (TiO2) xerogel monoliths were successfully synthesized by a facile sol–gel process accompanied by phase separation in the presence of formamide (FA) and triblock copolymer F127, followed by ambient pressure drying to remove the solvents. Gelation of the system has been mediated by FA, while F127 enhances a phase-separation. The resultant dried xerogel presents a hierarchically porous structure constructed by large macropores and mesoporous skeletons, which exhibits a high BET surface area of 444 m2 g−1. Heat-treatment at 800 °C results in the formation of the crystalline anatase phase with high thermal stability, without spoiling the macrostructure. The as- prepared porous TiO2 xerogel displays superior electrochemical properties, and the specific capacity of TiO2 xerogel could remain over 114 mAh g−1 (69 mAh cm−3) at 1 C after 100 cycles, representing a good cycling stability.