Ball-milled CuPc/TiO2 hybrid nanocomposite and its photocatalytic degradation of aqueous Rhodamine B

Abstract

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/TiO2 nanocomposite is still in the same structure of TiO2 and CuPc. SEM result reveals that the decreasing particle size of ball-milled CuPc has good dispersion on the surface of TiO2. 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 1wt.% CuPc/TiO2 nanocomposite with efficiency of 87.5% and reaction rate of 0.15min−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 TiO2 matrix.