Palygorskite supported BiVO4 photocatalyst for tetracycline hydrochloride removal.

A novel bismuth vanadate-palygorskite (BiVO 4 -Pal) photocatalyst was successfully prepared by a hydrothermal method. The morphology, structure and chemical composition of the composite was characterized. The adsorption capacity and photocatalytic activity under visible light of this composite to tetracycline hydrochloride were also investigated. The results indicated that BiVO 4 was successfully loaded on the Pal. Pal, as a low cost support, improved the adsorption capacity of the photocatalyst, thus increased the contact possibility with the active radicals, hence, the degradation activity of BiVO 4 was improved. The maximum adsorption capacity of BiVO 4 -Pal for tetracycline (TC), calculated by the Langmuir model at 20 °C, was 33.11 mg·g − 1 . The pseudo-first-order degradation rate constant for BiVO 4 -Pal composites was approximately 2.1 times higher than that of pure BiVO 4 , and the photodegradation ratio on the BiVO 4 -Pal composite was 1.4 times greater than that of pure BiVO 4 . In addition, the recovery of the BiVO 4 -Pal composite was carried out after the reaction by calcination at 400 °C for 4 h. The test showed that the prepared BiVO 4 -Pal catalyst was stable during the photodegradation of TC. There was no obvious reduction in the degradation rate of TC over the four successive runs and might be useful for practical applications. [ABSTRACT FROM AUTHOR]