Palygorskite supported BiVO4 photocatalyst for tetracycline hydrochloride removal

Abstract

A novel bismuth vanadate-palygorskite (BiVO4-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 BiVO4 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 BiVO4 was improved. The maximum adsorption capacity of BiVO4-Pal for tetracycline (TC), calculated by the Langmuir model at 20°C, was 33.11mg·g−1. The pseudo-first-order degradation rate constant for BiVO4-Pal composites was approximately 2.1 times higher than that of pure BiVO4, and the photodegradation ratio on the BiVO4-Pal composite was 1.4 times greater than that of pure BiVO4. In addition, the recovery of the BiVO4-Pal composite was carried out after the reaction by calcination at 400°C for 4h. The test showed that the prepared BiVO4-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.