Preparation Of Ph-and Temperature-sensitivity Metal Phthalocyanine/TiO₂Composite Photocatalyst And Its Study On Photocatalytic Activity

With the development of the society and economic, the problem of environmental pollution is becoming increasingly serious and has gradually affected people’s daily lives. Due to the excellent photocatalytic activity and physicochemical characteristics of TiO2, TiO2photocatalytic oxidation technology is being attached more importance as a new technique for disposal of contaminants. However, due to the defect of TiO2of easy reunion, difficult-to-recycle and the wide band gap, which means that only UV-light can be absorbed, this technique is highly restrained in the further development. The photosensitization of TiO2can extend the excitation wavelength, but the photo-quantum yield of this method is low and the composite photocatalyst formed is difficult to recycle.The intelligent polymeric hydrogel is a typical soft-solid material with3D network structures, which can be used as the carrier materials of nanoparticls. This could benefit the recycle of nanoparticls. In this paper, the synthetized cobalt tetra(N-carbonylacrylic)aminephthalocyanine(Co-MPc) was chosed as the sensitized material.a novel poly(NIPAM-co-AAc-co-Co-MPc)/TiO2composite photocatalyst was successfully synthesized by introduction of temperature sensitive non-ionic unit of poly N-isopropyl acrylamide (PNIPAM) and pH sensitive unit of Poly acrylic acid. This composite photocatalyst keeps favorable photocatalytic activity, good adsorption property and can be easily recycled. This provides both theoretical and practical basis for the industrialization of the TiO2photocatalytic technology. In this paper the main researches include the following parts:(1) A novel composite of poly(N-isopropylacrylamide-co-acrylic acid-co-cobalt tetra(N-carbonylacrylic)aminephthalocyanine)/titanium dioxide(TiO2) had been prepared via freeradical polymerization method. The composition, structure, and morphology of the novel composite were analyzed by fourier transform infrared spectra(FT-IR), transmission electron microscopy(TEM), X-ray Diffraction(XRD), thermogravimetric analysis(TGA) and UV-vis diffuse reflectance spectra(UV-Vis/DRS). The pH and temperature responsive properties of the composite were studied by observing the swelling ratio under various temperatures and pHs. The isoelectric point and adsorption property of this composite was studied.(2) Based on the degradation rate of the composite photocatalyst to2-sec-butyl-4.6-dinitrophenol(DNBP), The effects of catalyst preparation conditions such as the quantity of initiator, cross-linking agent. Co-MPc and TiO2were investigated and the optimized technological conditions and parametres were obtained.(3) The photocatalytic property of the composites was investigated for dedegradation of2-sec-butyl-4,6-dinitrophenol(DNBP) solution under visible light irradiation. The best factors to influence the photocatalytic property such as degradation time, pH of solution, catalyst concentration and DNBP concentration were obtained in the degradation process.(4) Choosing TiO2as photocatalyst, the degradation mechanisms of DNBP were studied and the probable mechanism was inferred.