Study on the preparation of ultrafine mesoporous TiO2 with controllable crystalline phase and its photocatalytic activities

Ultrafine mesoporous TiO2 was prepared via a sol–gel method with the template of PVP (polyvinylpyrrolidone). The photooxidated activity for decomposition of methyl orange and photoreduced activity for H2 evolution were evaluated after the template was extracted by refluxing acid–ethanol mixture at different compositions. The highest activity was achieved by treatment with the mixture of 3% acid content. In this proposed method, applied PVP template is of advantage to form mesostructure and high surface area, as well as controllable nanocrystalline phase based on a appropriate acid treatment.