Preparation of zinc tetraaminophthalocyanine sensitized TiO2 hollow nanospheres and their enhanced photocatalytic properties under visible light

A series of zinc tetraaminophthalocyanine (ZnPcN) sensitized TiO2 hollow nanospheres (ZnPcN/TiO2) with different loading dosages of ZnPcN were successfully synthesized by a simple immersion method under ultrasonic agitation. The as-prepared ZnPcN/TiO2 samples were characterized by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy, X-ray energy-dispersive spectrometry, Fourier transform infrared, and ultraviolet-vis diffuse reflectance spectrum. The results show that ZnPcN/TiO2 nanospheres composed of anatase crystalline phase with hollow structures have obvious absorption in the visible-light region. The photocatalytic activities of ZnPcN/TiO2 nanospheres were evaluated by degradation of C. I. Basic Blue 41 aqueous solutions with air as an oxidant under visible-light irradiation. The degradation results reveal that the photocatalytic activity of ZnPcN/TiO2 hollow nanospheres enhances a lot. The apparent rate constant of ZnPcN/TiO2 nanospheres with the mass ratio of 0.15% between ZnPcN and TiO2 is almost seven times higher than that of titania hollow nanospheres.