Preparation of Core/Shell Structured Rutile/Anatase Photocatalyst via Vapor Phase Hydrolysis and its Photocatalytic Degradation of Phenol and Methylene Blue

The core/shell structured rutile/anatase photocatalyst is prepared via a vapor phase hydrolysis process and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), N-2 adsorptiondesorption isotherm analysis, and Raman spectroscopy. TEM and HRTEM show that well crystalline anatase TiO2 is immobilized on the surface of rutile microspheres with dimensions of 200500 nm prior to calcination. The crystallite size of anatase in the shell ranges from 7.1 to 15.6 nm, which depends on the temperature and time of the vapor phase hydrolysis. N-2 adsorptiondesorption isotherm analysis shows that the photocatalyst is composed by micropores and mesopores. The photocatalytic performances of these catalysts in methylene blue and phenol are evaluated. The rutile/anatase photocatalyst has a relatively higher activity than pure rutile or anatase alone due to the synergistic effect of rutile and anatase.