Mesoporous TiO2 with Tunable Mixed Phase (Anatase/Rutile) and Morphology by Using Polyethyleneimine Modified F127 Block Copolymers as Templates for Enhanced Photocatalytic Performance

Polyethyleneimine (PEI) modified PluronicF127 block copolymers (PEI-F127-PEI) were synthesized via a chemical reaction of isocyanate and hydroxyl group. By using PEI-F127-PEI block copolymers as templates combined with a sol–gel process, followed by evaporation-driven assembly and calcination process, mesoporous TiO2 nanomaterials with different phase composition (rutile, anatase/rutile mixture, and anatase) and morphology were prepared. The prepared TiO2 samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectrophotometry and N2 adsorption analysis. It is found that the mass ratio of TiCl4/PEI-F127-PEI and calcination temperature have an important influence on the phase composition and morphology of TiO2. Compared to reported values, the transformation temperature from anatase to rutile decrease. When the mass ratio of TiCl4/PEI-F127-PEI is 2.0/1, the prepared sample exhibits the highest photocatalytic activity for the degradation of methylene blue (MB) under UV light irradiation, indicating that the mixed anatase/rutile phase TiO2 is an efficient photodegradation catalyst of MB pollutant in wastewater treatment.