Biosynthesized Bimetallic (ZnOSnO2) Nanoparticles for Photocatalytic Degradation of Organic Dyes and Pharmaceutical Pollutants

The quest for eco-friendly synthetic routes that can be used for the development of multifunctional materials, in particular for water treatment, has reinforced the use of plant extracts as replacement solvents. In this study, bimetallic ZnOSnO2 nanoparticles of different ratios were synthesized using the Sutherlandia frutescens (S. frutescens) plant and tested for the degradation of methylene blue dye and the antibiotics sulfisoxazole and sulfamethoxazole. From the analysis, FTIR confirmed the formation of bimetallic nanoparticles in all ratios within the fingerprint region. SEM revealed homogenous and heterostructures of tubular and spherical structures, with the size distribution ranging from 5-60 nm, respectively. XRD confirmed the formation and the crystallinity of the bimetallic nanoparticles, UV-Vis confirmed the optical properties of the materials and the bandgap values were found between 3.08 and 3.3 eV. From the surface area analysis, type III isotherm and mesoporous structures were confirmed. The photocatalytic activity of these ratios was investigated against MB dye and the antibiotics SSX and SMX. The highest degradation of 88% for MB was obtained using the 50:50 loading ratio at 150 min with a fast kinetic rate of 0.0008 min(-1). Furthermore, the holes were the species found to be responsible for the degradation of MB. The SSX and SMX antibiotics exhibited a 66% and 70% degradation, respectively. From this analysis, it can be noted that it is possible to synthesize environmentally safe materials that can be used to degrade various pollutants in our water streams.