Synthesis of Mesoporous Tungsten Trioxide with Crystalline Pore Wall at Low Hydrothermal Temperature

Abstract

Well-ordered hexagonal mesoporous tungsten trioxide with crystalline pore walls were synthesized at low hydrothermal temperature by using cationic quaternary ammonium gemini surfactants as structure-directing agents and sodium tungstate dihydrate (Na₂WO₄·2H₂O) as a precursor. The effects of alkyl chain length of gemini surfactants, hydrothermal temperature and molar ratio of tungsten to gemini surfactants have been investigated in detail. The strong self-assembly ability of gemini surfactants, strong electrical interaction between gemini surfactants and tungsten trioxide, and solvent extraction strategy contributed together to the coexistence of WO₃ mesostructures and crystalline pore walls.

Keywords:

• Crystalline pore walls
• gemini surfactants
• hexagonal mesostructure
• tungsten oxides

This research was financially supported by the Key Project Foundation of the Ministry of Education of China (No. 105104), the Natural Science Foundation of China (No. 50572057), the Middle-Aged and Youthful Excellent Scientist Encouragement Foundation of Shandong (No. 2005BS1–1003), the Natural Science Foundation of Shandong Province (No. Z2006B02), and the Science and Technology Development Plan of Shandong Province (No. 2007GG20006002).