Synthesis Of V₂O₅/Alkylviologen Intercalation Compounds And Their Photocatalytic Performace For Dye Degradation

The photocatalytic oxidation was developed from 1970s, which was called "green technique" and "environmental benign technique". Photocatalysis can effectively oxide organic pollutants into inorganic molecules, and is a good dirty water processing method. Layered inorganic materials have been extensively studied due to their ability to be intercalated by different guest molecules. On the basis of this function, many novel assembly structures can be tailored at the molecular level through the design of the host and the guest species. Thus it provides a vast technique space and application foreground for the synthesis of novel photocatalysts.In this thesis, layered vanadium pentoxide was investigated as inorganic host, alkylviologen dications were selected as organic guest, respectively. A novel series of inorganic-organic intercalation compounds were prepared, which were abbreviated RV₂. These intercalation compounds were characterized by XRD, FT-IR, XPS, UV-vis DRS and so on. Dye degradation was performed to evaluate the photocatalytic performance of the intercalation materials, and probe the relationship of the photocatalytic performance and the structure of the catalysts.The analytical results confirmed that the molecular formula of the intercalation compounds were presented as (RV)_0.25V₂O₅. The interlayer spacing of the organic-inorganic intercalation compounds increases with the increase of the alkyl chain in the alkylviologen cations. The phase of vanadium oxides in the intercalation compounds is composed of mixed-valence vanadium oxides. The synergic effect of the guest and the host can lead to the stabilization of the excited state of organic guest. The analysis of UV-Vis DRS shows that the intercalation compounds have the absorption character within ultraviolet and visible light region owing to the interaction between such guest and host.The photocatalytic degradation of MB and CR were investigated in the aqueous heterogeneous suspensions with RV₂ as photo-catalysts irradiating with 500W halogen tungsten lamp. The aqueous MB solution (100ml, 10mg.L^-1) containing theHV₂ at a concentration of 0.20g.L^-1. After reacting for 5 hours, the decomposition of MB can be reached 99% above. The aqueous CR solution (100ml, 20mg.L^-1) containing the PeV₂ at a concentration of 0.20g.L^-1. After reacting for 3 hours, the decomposition of MB can be reached 98% above. Comparison with the photocatalytic degradation of MB and CR in the literature, the result of the thesis exhibits lower energy exhausted and lower cost.The photocatalytic degradation of IC and CV were investigated in the aqueous heterogeneous suspensions with RV₂ as photo-catalysts irradiating and UV lamp as light source. The relationship of the structure and the photocatalytic performance was investigated. The experimental results indicated that growth of the alkyl chain in alkylviologen influence the adsorption of intercalation compound to dye in water, hence influence the photocatalytic reactivity. So catalysts with strong photocatalytic reactivity can be synthesized from adjusting different organic guests.