Sensitization of ZnO nanoparticles by metal-free phthalocyanine

Metal-free phthalocyanine (PC) as an efficient dye sensitizer was successfully used to prepare a hybrid compound based on ZnO nanoparticles. The PC/ZnO sample is synthesized via a simple solution method and characterized by XRD, TGA, FTIR, PL, TEM, and UV-visible spectroscopy. The results show that the phase component and morphology do not change due to the modification process. The weight ratio of ZnO to PC in the PC/ZnO sample is estimated to be about 9, based on the TG analysis. The FTIR spectroscopy shows that (i) a new band appears at 749 cm(-1) (assigned to the C-H bending vibration) and (ii) the hydroxyl stretching vibrations is intensified (due to the increase in surface defects and approved by PL spectroscopy). Both are evidences for the creation of conjugate between ZnO NPs and PC molecules. The main influence of this process is to change in the UV-visible absorption behavior of the sample. The UV-visible spectrum shows a wide peak in the wavelength range of 280-320 nm, with the maximum peak at 274 nm (assigned to the Soret band), approving enhancement of its photoactivity.