Harnessing wasted mushroom peel aqueous extract for mycogenic synthesis of zinc oxide nanoparticles for solar photocatalysis and antimicrobial applications

A sustainable method for the green synthesis of zinc oxide nanoparticles, ZnO-as synthesized (ZnO-Mu), employing an aqueous solution of mushroom (Agaricus bisporus) peel extract has been described in this study. Pure zinc oxide, ZnO-annealed (ZnO-Pu), has been fabricated by heating ZnO-Mu to 500 °C for 2 h. A number of physicochemical techniques, which include Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (TEM), and X-ray diffraction (XRD), were used to examine the morphological, structural, thermal, optical, and spectral properties of ZnO-Mu and ZnO-Pu. The average crystal size for both ZnO-Mu and ZnO-Pu has been calculated, resulting in 9.338 nm and 14.534 nm, respectively. The grain size range is 15–25 nm and 80–90 nm for ZnO-Mu and ZnO-Pu, respectively. As a model organic pollutant, methylene blue dye (MB) was employed in the study of ZnO-Mu and ZnO-Pu photocatalytic efficiencies under solar irradiation. Investigating the effects of operating factors such as photocatalyst dosage, reaction time, and pH was done in order to determine the ideal conditions for photocatalytic degradation. Under optimal conditions, nearly 97.14% of the MB was photodegraded in 40 min. The antimicrobial characteristics of ZnO-Mu and ZnO-Pu have been studied before and after their exposure to different light sources: visible light, UV light (265 and 346 nm) against Bacillus cereus (MW830387), Escherichia coli (MW534699), Enterococcus faecium (OQ073495), and Pseudomonas aeruginosa (OP890578). Also, studied fungal species were Aspergillus niger (MW596373), Penicillium polonicum (MT550029.1), Pythium ultimum (MW830915), and Verticillium dahliae (MW830379). Both ZnO-Mu and ZnO-Pu represent promising antimicrobial activity, especially ZnO-Pu exposed to UV (265 nm), which demonstrated the highest inhibition.