Rapid Preparation of Uniform High-Crystallized Mesoporous Titania Spheres without High-Temperature Treatment

It is of such importance to prepare functional inorganic materials using a high-efficiency and low-cost strategy. In this work, uniform high-crystallized mesoporous titania (TiO2) spheres are successfully synthesized via an advanced method. On the one hand, not only are the mesoporous anatase TiO2 spheres well-crystallized without any high-temperature treatment but the total reaction time also can be largely shortened compared to the previous methods. On the other hand, the TiO2 spheres still retain their high porosity and have a high specific surface area. Besides, the organic structure-directing agent can be cycled and used, being a representative of the rapid, effective, green, and low-cost methods. First, the systematical research studies are conducted by monitoring the formation process of the TiO2 spheres in two kinds of reaction solutions using scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectrum technologies. The results demonstrate that the mixed water/ethanol solution can be used to rapidly prepare the mesoporous TiO2 spheres owing to the catalysis of water, compared to the single ethanol solution. Then, feasible mechanisms are proposed for the mesoporous TiO2 spheres obtained in different solutions. Next, the preparation method is improved to avoid the appearance of separated nanoparticles, and thus, the uniform high-crystallized mesoporous TiO2 spheres are successfully fabricated within only 4 h reaction time. Finally, the mesoporous TiO2 spheres are employed as electrode materials and proved to be a promising anode of lithium-ion batteries.