Ball-milled CuPc/TiO_2 hybrid nanocomposite and its photocatalytic degradation of aqueous Rhodamine B

摘要

Hybrid composites of titanium dioxide and copper phthalocyanine were synthesized by ball-milling assisted process in combination with mechanically stirring method. Structural properties of as-synthesized composites were characterized by X-ray diffraction (XRD), X-ray absorption fine structure (XANES) and scanning electron microscope (SEM). The optical absorbance of as-prepared composites and their photocatalytic activities were investigated by UV-vis spectroscopy. XRD and XANES results confirm that CuPc/TiO_2 nanocomposite is still in the same structure of TiO_2 and CuPc. SEM result reveals that the decreasing particle size of ball-milled CuPc has good dispersion on the surface of TiO_2. Absorptivity in UV region of the composites is heightened and shifted to visible light due to strong absorbance in blue-green spectrum of CuPc. The photocatalytic degradation of Rhodamine B dye solution using as-synthesized composites was investigated under ultraviolet irradiation. The optimized condition for RhB photodegradation was obtained for 1 wt.% CuPc/TiO_2 nanocomposite with efficiency of 87.5% and reaction rate of 0.15 min~(-1). The significant improvement in photocatalytic activity of the hybrid composite may be associated to the enhancement of optical absorption and the inhibition of electron-hole recombination caused by the presence of CuPc in TiO_2 matrix.