In thefirst project, hydroxyapatite/TiO 2 /ZnO (HAP/TiO 2 /ZnO) composites were prepared by sol-gel method. The photocatalyst was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis) and transmission electron microscopy (TEM). The photocatalytic activity of the photocatalyst was evaluated by photocatalytic degradation of acid orange (AO) aqueous solutions under visible light and UV irradiation. The results showed that the photocatalytic activity of the hydroxyapatite/TiO 2 /ZnO is much higher than that of hydroxyapatite/TiO 2 on the photodegradation process. The effects of operational parameters such as the amount of photocatalyst, initial concentration of azo dye, pH, on the photocatalytic activity of the photocatalyst were also investigated. In the second project HAP/FeCl 3 was prepared by impregnation method. Then the nanocatalyst was characterized by TEM, FT-IR, SEM, XRD and UV-vis and was tested for Friedel–Crafts alkylation. The various parameters such as time, temperature, %w FeCl 3 , amount of the catalyst were optimized. In the third project, Co-Mn nanocatalyst was prepared by using of osmosis and impregnation methods. The nanocatalyst was characterized by XRD, TEM, FT-IR, SEM, BET, and UV-vis techniques and was tested for oxidation of diphenylmethane to benzophenone. The nanocatalyst exhibited high catalytic activities for the oxidation of diphenylmethane under heterogeneous conditions. In order to obtain maximum conversion, the reaction parameters such as reaction temperature, time, amount of the nanocatalyst and pressure of oxygen gas were optimized. Under the optimized conditions, a maximum of 87% conversion and 90% selectivity, was achieved with heterogeneous hybrid Co/Mn nanocatalyst over calcined bone. The reaction did not proceed in the absence of the catalyst. Benzophenone was the major product and the other products were found to be benzoic acid and a little amount of other products .The catalyst can be recovered and recycled by a simple decantation.
