Photoconductive and Antimicrobial Properties of Psidium guajava Leaf Extract Mediated Green Synthesized SnS2–CdO and SnS2–NiO Nanocomposites

This paper reports the photoconductive and antimicrobial properties of SnS2–CdO and SnS2-NiO nanocomposites green synthesized using Psidium guajava leaf extract. X-ray diffraction studies reveal that the SnS2–CdO nanocomposite exhibits hexagonal SnS2 and cubic CdO diffraction peaks; whereas the SnS2–NiO nanocomposite exhibits hexagonal SnS2 and cubic NiO diffraction peaks. SEM image of the bio-synthesized SnS2–CdO nanocomposite confirmed nanoneedles with grains being well distributed. Regular shaped grains with decreased sizes were observed for the SnS2–NiO nanocomposite. Nanosized grains were observed from the TEM images. The existence of elements Sn, S, Cd, O in SnS2–CdO nanocomposite; Sn, S, Ni, O in SnS2–NiO nanocomposite was confirmed from the EDX and XPS spectra. Increased photosensitivity value was realized for the SnS2–CdO nanocomposite. Both the composites showed good fungal inhibition property against Aspergillus terreus fungi not only by the physical, chemical and biological processes but also owing to phyto-constituents in the leaf extract.