Synthesis And Photocatalytic Activity Of Alkoxyl Phthalocyanine/SnO₂/TiO₂Composite Material

In recent years, compound semiconductor photocatalytic oxidation technologyhas important significance in environmental pollution. As the light range ofcompound was broadened comparing to semiconductor, but the utilization of solarenergy is low and only ultraviolet part can be absorbed.So how to sensitize it becomesa very important issue of current research.Metal phthalocyanine (MPc) has been usedto be sensitizer for a long time because of its intensively absorbing visible light. If it isused for the sensitization of compound semiconductor, it can make the photocatalyticmaterials be more excellent performance.In this paper, the subsitituted phthalocyanine with good solubility andpreparation of relatively simple was selected as sensitizer. First, while SnO2/TiO2gelmatrix has been formed with Co(Ⅱ) as template with adjacent4-nitro-phthalonitriletetramerization, TNPcCo/SnO2/TiO2were synthesized in-situ on the surface ofSnO2/TiO2nanoparticles, then the composite material were prepared with differentmolar ratios. Then a series of precursor bodys were prepared via nucleophilicsubstitution of the alpha-naphthol, phenol,8-hydroxyquinoline, five chlorine phenolbe reacted with4-nitro-dicyanobenzens, and the above method were used to preparedifferent molar ratios of four kinds ArO-CoPc/SnO2/TiO2.the prepared products werecharacterized by IR、UV-Vis、XRD and TG methods, and it’s photocatalytic activityof the composite materials with Rhodamine B under visible light were measured.The UV-Vis spectrum of metal phthalocyanine be moving to long wavelength inits characteristic absorption Q-band with the increasing of the molar ratio; differentmolar ratios of the composite materials in the IR spectrum can discover the vibrationabsorption peaks of Co-O; Immobilizing of metal phthalocyanine did not change thecrystalline form of compound semiconductor, but the grain growth was hindered andthe size had become smaller in XRD spectrum; the pyrolysis temperature of TNPcCoin composite material is higher than TNPcCo in the curve of TG analysis.Thisindicates that means of in-situ can improve the stability of composite materials.In visible Rhodamine B degradation experiments, the degradation rate ofcomposite materials are all highly than SnO2/TiO2, and the degradation rate of fourkinds substituents of composite materials are all highly than TNPcCo/SnO2/TiO2. Itmeans that introduction of substituents have a certain influence on the catalyticefficiency. the best photocatalytic activity was respectively found inCoPc(-OC6Cl5)4/SnO2/TiO2and the catalytic efficiency of CoPc(β-OC12H6N)4/SnO2/TiO2was relatively low. This suggests that differentsubstituents on the composite photocatalyst also have a greater impact.Photocatalytic stability experiments indicated that photocatalytic degradationefficiency of mol%TNPcCo/SnO2/TiO2was almost unchanged and the toxicosisand inactivation didn’t appeared. This indicated that the chemical bond formationbetween TNPcCo and SnO2/TiO2is relatively stable.