| Supported photocatalyst have attracted more attention by right of itsstability, recoverability, and efficiency of photocatalytic degradation. Bentoniteis adapt to be supporters, because it has large specific surface aera, excellentstability and adsorbability. So preparing TiO2/bentonite photocatalyst withhigher photocatayse ability has extensive application future and environmentalsignificance.In this paper, TiO2 nanoparticles generate in situ in the adsorption layer oforganophilic bentonite, because the adsorption layer on the surface oforganophilic bentonite/liquid interface can be used as a micro reactor, and theprecursor ions can be preferentially adsorped with ethanol by organophilicbentonite. Then the TiO2/organophilic bentonite composite material can beprepared. The structure of the composite material and the size of TiO2nanoparticles are studied by XRD, IR, DSC and SEM. The results show theorganophilic bentonite particles which are dispersed in ethanol-cyclohexanebinary mixtures can be used as micro reactors which have enough space for thegenerated of TiO2 nanoparticles in their adsorption layers when the molarfraction of ethanol is 0.19, and the concentration of the suspensions oforganophilic bentonite is 10 g·L-1. The distance of interracial layer on thecomposite material extends to 3.59 nm. The photocatalytic degradation rate of the composite material on phenol and methylene blue under ultraviolet light arestudied, and the effects of phenol initial concentration, dosage of compositematerial, pH value and reaction time on the photocatalytic degradation rate ofphenol and methylene blue are discussed. The results indicate that thephotocatalytic degradation efficiency using the composite material withouttreatment under high temperature is relatively higher. The results show theoptimun photocatalytic degradation conditions for phenol as follow: pH is 7,dosage of composite material is 2.5 g·L-1, and reaction time is 1 hour; formethylene blue as follow: pH is 12, dosage of composite material is 2.0 g·L-1,and reaction time is 1 hour. Hydrogen peroxide can improve the photocatalyticdegradation efficiency, shorten the reaction time and accelerate the process thatorganic molecult turn to be mineral. |
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