Zirconium metal-organic framework supported highly-dispersed nanosized BiVO4 for enhanced visible-light photocatalytic applications

BACKGROUND: As a super stable zirconium based metal-organic framework, Zr-6(OH)(4)(C8H6O4)(6) (UiO-66) is considered a competitive candidate to conjugate with photocatalyst to enhance photocatalytic activity. In this study, highly dispersed bismuth vanadate (BiVO4) nanoparticles grown in situ upon the surfaces of UiO-66 were synthesized through a simple method, and the photocatalytic activities were investigated by measuring the degradation of rhodamine B (RhB) under visible light irradiation. RESULTS: The results show that UiO-66@BiVO4 composite with Bi:Zr molar ratio of (1:1) was the optimum hybrid and exhibited much higher photocatalytic activities than that of pure BiVO4. Furthermore, the photocatalyitc mechanism of RhB degradation by UiO-66@BiVO4 was also investigated, the photodegradation of RhB was mainly caused by the super oxide ions (center dot O-2(-)). The lone pair electrons of surface group -OH and -COOH of UiO-66 attract the photogenerated holes (h(+)), which effectively prevent the recombination of electrons and holes. CONCLUSIONS: The enhanced separation of photogenerated electron- hole pairs through interfaces between BiVO4 and UiO-66 led to improvement of the photocatalytic activity. The study showed a degradation mechanism for RhB wasterwater treatment. (C) 2016 Society of Chemical Industry