Sustainable approach of La doped CuFe2O4 nanomaterial for electrochemical lead and paracetamol sensing action with multiple applications

This present research aimed to investigate the novel applications of synthesized La doped CuFe2O4 nanomaterial (LCF NMs) using renewable bio-fuel (Aegle Marmelos extract) by combustion process. The sensor applications were accomplished by modified electrode using LCF NMs with graphite powder and examined its excellent sensing action towards heavy metal (Lead content) and drug chemical (Paracetamol) substances. The thermodynamics of redox potential and super-capacitor behavior of LCF NMs were investigated through Cyclic Voltametric (CV) and Electrochemical Impedance Spectral (EIS) methods under specific conditions at scan rate of 1 to 5 mV/s. The heterogeneous photo-catalytic process of prepared NMs on Fast orange Red (FOR) dye-decolouration was investigated and noted its excellent degradation (91.7%) at 90 min using 20 ppm of dye solution and 40 mg of synthesized samples under Sun-light irradiation. Further, the antibacterial activity of synthesized NMs is investigated against various strains of gram positive (Bacillus subtillis) and gram negative bacteria (Pseudomonas aeruginosa), which confirms that the LCF NMs have higher activity towards gram positive bacteria with an average inhibition zone of 19 mm. This synthesized LCF NMs is a multi-functional material with stable and eco-friendly materials.

Synergistic effect of a Bi2Zr2O7 and hydroxyapatite composite: organic pollutant remediation, antibacterial and electrochemical sensing applications

Global concern regarding the energy crisis and environmental pollution is increasing. The fabrication of efficient catalysts remains a long-term goal. Recently, green synthesis methods for catalyst fabrication have attracted the scientific community. Herein, a simple approach to synthesize bismuth zirconate-hydroxyapatite (BZO-HA) nanocomposites using Mentha spicata (mint) leaves as a reducing agent via a combustion method has been reported. The use of a green reducing agent provided economic attributes to this work. Among the prepared samples, the BZO-HA (20%) composite exhibited superior photocatalytic activity. The photodegradation efficiency of the composite reached 90.3% and 98.4% for methylene blue (MB) and rose Bengal (RB) dyes, respectively. The results showed the excellent optical performance of the prepared composites. The constructed sensor (BZO-HA 20%) for the very first time showed outstanding selectivity and performance towards sensing lead nitrate and dextrose compared to bare bismuth zirconate (BZO) and hydroxyapatite (HA). A three-electrode system using 0.1 M KCl was used for the study. The synthesized composite BZO-HA (20%) can sense lead nitrate and dextrose over the concentration range of 1-5 mM in the potential range from -1.0 V to +1.0 V. The BZO-HA composite was also investigated against Gram-negative (S. typhi) and Gram-positive (S. aureus) bacteria for antibacterial activity studies. Enhanced antibacterial activity was observed compared to bare BZO and HA catalysts. Thus, the prepared BZO-HA nanocomposite exhibited multifunctional applications.

Influence of Ag on the Structural, Electrochemical, Antibacterial, and Photocatalytic Performance of the (CuO-Cu2O)Cu Nanocomposite

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 3d_5/2 (367.9 eV) and Ag 3d_3/2 (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.

Leucas aspera mediated multifunctional CeO2 nanoparticles: Structural, photoluminescent, photocatalytic and antibacterial properties

Spherical shaped cerium dioxide (CeO2) nanoparticles (NPs) were synthesized via bio mediated route using Leucas aspera (LA) leaf extract. The NPs were characterized by PXRD, SEM, UV-Visible techniques. Photoluminescence (PL), photocatalysis and antibacterial properties of NPs were studied. PXRD patterns and Rietveld analysis confirm cubic fluorite structure with space group Fm-3m. SEM results evident that morphology of the NPs was greatly influenced by the concentration of LA leaf extract in the reaction mixture. The band gap energy of the NPs was found to be in the range of 2.98-3.4 eV. The photocatalytic activity of NPs was evaluated by decolorization of Rhodamine-B (RhB) under UVA and Sun light irradiation. CeO2 NPs show intense blue emission with CIE coordinates (0.14, 0.22) and average color coordinated temperature value ∼148,953 K. Therefore the present NPs quite useful for cool LEDs. The superior photocatalytic activity was observed for CeO2 NPs with 20 ml LA under both UVA and Sunlight irradiation. The enhanced photocatalytic activity and photoluminescent properties were attributed to defect induced band gap engineered CeO2 NPs. Further, CeO2 with 20 ml LA exhibit significant antibacterial activity against Escherichia coli (EC) and Staphylococcus aureus (SA). These findings show great promise of CeO2 NPs as multifunctional material for various applications.