In the current research work, bismuth doped tin-dioxide (Bi-SnO2) was prepared by wet chemical co-precipitation method. The synthesized material was used as a photocatalyst in the degradation of congo red dye (CR) in its aqueous solution. The prepared catalyst was used in the uncalcined- and calcined forms for the photocatalytic reaction. The synthesized catalyst in both forms was characterized by UV-visible spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD revealed that the calcination of the Bi-SnO2 improved its crystallinity. The SEM showed that the Bi-SnO2 had average size less than 150nm. Photocatalytic degradation of CR dye was carried out under ultra-violet light as well as under sunlight. While testing the photocatalytic degradation performance, it was found that more than 80% of the CR was degraded by using Bi-SnO2 nanoparticles under both lighting conditions. Moreover, the calcined Bi-SnO2 nanoparticles showed better photocatalytic performance as compared to its uncalcined form. The present work provides a viable way to make efficient photocatalyst based-on Bi-SnO2 to employ under UV and sunlight for the degradation of the CR dye without the need of oxidizing or reducing agents.

Nauman Ali, Adnan khan, Aaisha Riaz, Abdullah M. Asiri and Tahseen Kamal