Biosynthesis of SnO₂ nanoparticles by aqueous leaf extract of Calotropis gigantea for photocatalytic applications

Here we developed biogenic route for the synthesis of SnO₂ NPs by using aqueous leaf extract of Calotropis gigantea which acts as reducing and stabilizing agent. The biosynthesized SnO₂ NPs were characterized by different characterization techniques such as UV–visible diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis and high resolution transmission electron microscope. XRD pattern shows tetragonal structure of SnO₂ NPs with 35 nm size. The FT-IR spectra of aqueous leaf extract shows the presence of hydroxyl group, aldehydes, amines and aromatic rings which are responsible for biochemical transformation. The FE-SEM analysis suggests mixed morphology with slight agglomeration. DRS absorption spectrum indicates the band gap is about 3.1 eV. The photocatalytic activity of the synthesized SnO₂ NPs checked for the degradation of Methyl Orange and found up to 80% degradation within 3 h under UV–visible light.