RESUMO
Novel visible-light-driven Ag (X)-doped Bi2Zr2O7 (BZO) nanocomposites in pudina (P) extract (Mentha spicata L.), X-1, 3, 5, 7, and 9 mol %, were synthesized by the one-pot greener solution combustion method. The as-synthesized nanocomposite materials were characterized by using various spectral [X-ray diffraction (XRD), Fourier transform infrared, UV-visible, UV- diffuse reflectance spectra, X-ray photoelectron spectroscopy], electrochemical (cyclic voltammetry, electrochemical impedance spectroscopy), and analytical (scanning electron microscopy-energy-dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller) techniques. The average particle size of the nanocomposite material was found to be between 14.8 and 39.2 nm by XRD. The well-characterized Ag-doped BZOP nanocomposite materials exhibited enhanced photocatalytic degradation activity toward hazardous dyes such as methylene blue (MB) and rose bengal (RB) under visible light irradiation ranges between 400 and 800 nm due to their low energy band gap. As a result, 7 mol % of Ag-doped BZOP nanocomposite material exhibited excellent photodegradation activity against MB (D.E. = 98.7%) and RB (D.E. = 99.3%) as compared to other Ag-doped BZOP nanocomposite materials and pure BZOP nanocomposite, respectively, due to enhanced semiconducting and optical behaviors, high binding energy, and mechanical and thermal stabilities. The Ag-doped BZOP nanocomposite material-based electrochemical sensor showed good sensing ability toward the determination of lead nitrate and dextrose with the lowest limit of detection (LOD) of 18 µM and 12 µM, respectively. Furthermore, as a result of the initial antibacterial screening study, the Ag-doped BZOP nanocomposite material was found to be more effective against Gram-negative bacteria (Escherichia coli) as compared to Gram-positive (Staphylococcus aureus) bacteria. The scavenger study reveals that radicals such as O2â¢- and â¢OH are responsible for MB and RB mineralization. TOC removal percentages were found to be 96.8 and 98.5% for MB and RB dyes, and experimental data reveal that the Ag-doped BZOP enhances the radical (O2â¢- and â¢OH) formation and MB and RB degradation under visible-light irradiation.
RESUMO
The cost-effective novel Ag-doped (1-7%) (CuO-Cu2O)Cu (C3) heterostructured nanocomposites are successfully synthesized by the facile solution combustion process using the Leucas aspera extract as a green fuel. The structural properties of fabricated nanocomposites were well-characterized by specific spectral techniques for enhanced electrochemical sensor detection, antibacterial activities, and sunlight-driven photocatalytic dye decoloration studies. The existence of Ag+ ions has been confirmed by the appearance of two peaks of Ag 3d5/2 (367.9 eV) and Ag 3d3/2 (373.9 eV), with the chemical binding nature and exchange of the Ag+ state in the nanocomposite lattice as revealed by X-ray photoelectron spectroscopy analysis. The energy band gap value of the doped nanocomposite decreases from 2.2 to 1.8 eV, as measured by the UV-visible absorption spectral technique, hindering the recombination of electron-holes pairs by trapping e- and h+. This result supports that the C3Ag5 nanocomposite has a great potential as a sunlight photocatalyst toward the Alizarin Red (AR) dye, for which an excellent degradation activity of 98% at 180 min was achieved compared to that of the host nanocomposite (78% at 180 min). The variation of redox peak potentials of the prepared graphite nanocomposite working electrode is an effective tool for paracetamol sensing activity in 0.1 M KCl using electrochemical spectral studies. In addition, the antibacterial activities of the C3Ag5 nanocomposite against Escherichia coli and Staphylococcus aureus were successfully studied. The C3Ag5 nanocomposite exhibited a better performance than C3. The increase in activity is attributed to the presence of Ag as a dopant.