在常溫下，使用最適觸媒及最適添加量，200ppm乙酸，反應3小時COD去除率可達41.6%。 This study aimed at the improvement of TiO2 photocatalyst. There are two objectives in this work: First, via sol-gel method, the TiO2 and apatite were synthesized respectively. Second, considering the great oxidation capability of TiO2 and the great organics adsorption capacity of apatite, the TiO2 and apatite were blended to have the best of both worlds. Note that TiO2 and apatite are compatible. The acetic acid was choosen as the reactant because it is a refractory organic and is stable even under the irradiation of UV ray. TiO2/apatite catalysts with various ratios were prepared and investigated. It is for screening for the optimum ratio of TiO2/apatite. Besides, the optimum catalyst loading was also determined.
According to XRD spectra analysis, the TiO2 prepared by using TiCl4 is predominantly the anatase phase. It was found that amount of residual Cl- would affect powder size and specific surface area of TiO2. Alternatively, adding appropriate amount of polypropylene (PP) could increase specific surface area of apatite. The optimum apatite/PP ratio is 1:1. In addition, results of acetic acid reaction showed that the optimum ratio of TiO2/apatite is 1:1, whilst the optimum catalyst loading is 0.75g/L. Under the most efficient condition, the COD removal of 200 ppm acetic acid solution could attain 41.6% after 3hrs reaction.