Azadirachta indica peel extract-mediated synthesis of ZnO nanoparticles for antimicrobial, supercapacitor and photocatalytic applications

In this work, flake-shaped zinc oxide (ZnO) nanoparticles (NPs) labeled as (P3) are green synthesized using Azadirachta indica fruit peel extract for antibacterial, supercapacitor, and photocatalytic applications. XRD pattern revealed the hexagonal wurtzite crystalline structure of the green synthesized ZnO NPs while FTIR spectrum confirmed their surface-attached phytochemicals coating. FE-SEM image demonstrated micro to nano-sized flake-shaped ZnO NPs with widths 116-145 nm and lengths 215-398 nm. The surface area of synthesized ZnO NPs was obtained as 22.721 m(2)/g using Brunauer-Emmett-Teller (BET) analysis. Minimum inhibitory concentration (MIC) values of as-prepared ZnO NPs are determined as 140, 135, and 130 mu g/mL against Escherichia coli, Pseudomonas aeruginosa, and both Staphylococcus aureus and Streptococcus pneumoniae, respectively. Moreover, as-synthesized ZnO NPs showed high specific capacitance and energy density values of 794.96 F/g and 22.34 Wh/kg at 5 mV/s, respectively. Furthermore, as-prepared ZnO NPs showed 88.53% and 83.08% photocatalytic degradation for methylene blue and rhodamine B dye, respectively, after 240 min of sunlight exposure. In summary, green synthesized flake-shaped ZnO NPs are promising candidates for antibacterial, supercapacitor, and photocatalytic applications. [GRAPHICS]