Fabrication of the novel core-shell MCM-41@mTiO2 composite microspheres with large specific surface area for enhanced photocatalytic degradation of dinitro butyl phenol (DNBP)

The mesoporous MCM-41@mTiO 2 core-shell composite microspheres were synthesized successfully by combining sol-gel and simple hydrothermal treatment. The morphology and microstructure characteristics of the synthesized materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption measurements, X-ray powder diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis/DRS) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the composite material possesses obvious core/shell structure, a pure mesoporous and well-crystallized TiO 2 layer (mTiO 2 ), high specific surface area (316.8   m 2 /g), large pore volume (0.42   cm 3 /g) and two different pore sizes (2.6   nm and 11.0   nm). The photocatalytic activity of the novel MCM-41@mTiO 2 composite was evaluated by degrading 2- sec -butyl-4,6-dinitrophenol (DNBP) in aqueous suspension under UV and visible light irradiation. The results were compared with commercial anatase TiO 2 and Degussa P25 and the enhanced degradation were obtained with the synthesized MCM-41@mTiO 2 composite under the same conditions, which meant that this material can serve as an efficient photocatalyst for the degradation of hazardous organic pollutants in wastewaters.