The widespread contamination of Bisphenol A (BPA) in the aquatic system poses serious environmental and ecological concerns due to its persistent and endocrine-disrupting properties, necessitating efficient strategies for its management. The present study was planned to develop silver-doped titanium dioxide nanoparticles (Ag-TiO₂ NPs) as an efficient photocatalyst for BPA degradation in the aquatic system. The synthesized nanoparticles were characterized using UV-VIS spectroscopy, FT-IR, XRD, SEM-EDX, BET, and particle size analyzer for their structural, optical, morphological, and surface characteristics. The particle size of synthesized TiO2 NPs and Ag-TiO2 NPs was ranged to be 25–50 and 35–65 nm with average particle size of 37 and 49.9, respectively. Surface plasmon resonance behavior and reduced band gap energy confirmed successful incorporation of Ag into the TiO₂ matrix, resulting in enhanced UV-light absorption and improved charge separation efficiency. BET analysis confirmed the mesoporous nature, possessing pore diameters of 4–6 nm. Overall, Ag-TiO₂ NPs demonstrated up to 90.50
Riboflavin (C17H20N4O6) is an essential water-soluble vitamin B2, and its precise assessment is vital for food quality control, pharmaceutical analysis, and nutritional monitoring. In this work, an L-valine-modified manganese-doped nickel chromate oxide carbon paste electrode (L-VM/Mn-NiCr2O4-CPE) was prepared by using a combustion-synthesized Mn-NiCr2O4 nanohybrid for the electrochemical determination of riboflavin. The synthesized nanomaterial was systematically characterized using energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Raman spectroscopy to investigate its elemental composition, surface morphology, crystal structure, and vibrational properties, respectively. Then, the electrochemical behaviour of the prepared electrode was studied using cyclic voltammetry (CV), linear sweep voltammetry (LSV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The optimized settings demonstrated that the sensor response was linear in the concentration range of 0.020–0.280 µM with detection limits of 0.092 µM (CV), 0.115 µM (LSV), and 0.088 µM (DPV). The fabricated sensor exhibited good analytical performance with repeatability relative standard deviation (RSD) less than 0.68
Methanolysis represents a promising route for the chemical recycling of poly(ethylene terephthalate) (PET), enabling the recovery of valuable monomers like dimethyl terephthalate (DMT). Herein, we report the synthesis and catalytic evaluation of a novel bifunctional CaO/CeO2 heterogeneous catalyst for efficient PET depolymerization. Octahedral CeO2 particles (21.6 nm crystallite size) with a face-centered cubic (FCC) structure were hydrothermally synthesized and subsequently modified with CaO via wet impregnation, yielding an average hydrodynamic diameter of 850 nm. Catalytic reactions in a closed batch reactor demonstrated that CaO/CeO2 significantly outperforms both non-catalytic and pristine CeO2 systems. Under optimized conditions (220 °C, 1 h, 5 wt
This work presents the electrochemical determination of Fast Sulphon Black F (FBF) using a carbon nanotube paste electrode modified with an electrochemically polymerized L-threonine film (PLTRCNTE). The use of an electrochemically polymerized L-threonine film on a carbon nanotube paste electrode for the determination of FBF is the main novelty of this work. The electrochemical response of FBF was optimized in 0.2 M phosphate buffer solution (PBS) at pH 6.0, providing a sensitive and reliable analytical signal. The structural and morphological characteristics of the fabricated PLTRCNTE and the bare carbon nanotube paste electrode (BCNTE) were examined by scanning electron microscopy (SEM). The electrochemical properties of the electrodes were further investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The influence of possible interfering metal ions and organic species was also evaluated, demonstrating satisfactory selectivity of the proposed sensor. Scan rate analysis indicated that the oxidation process of FBF is a mixed adsorption and diffusion process close to adsorption. Furthermore, the effects of key experimental variables, including solution pH, accumulation potential, and analyte concentration, were systematically optimized. Under the optimized conditions, the PLTRCNTE exhibited excellent analytical performance, achieving a limit of detection (LOD) of 0.16 µM and a limit of quantification (LOQ) of 0.56 µM. In addition, the developed sensor displayed excellent repeatability, reproducibility, and long-term stability.
The adsorption and oxidation of propylene on a rutile TiO2(110) surface and the effect of UV light illumination on those processes are studied using thermal desorption spectroscopy. Propylene adsorbs molecularly on the clean surface. Epoxidation with pre-adsorbed O2 to form propylene epoxide and oxygen adatoms occurs at about 158 K at sub-monolayer coverages, but not at the monolayer saturation due to the lack of vacant Ti sites. UV light illumination at the monolayer saturation induces the partial desorption of adsorbed propylene and the partial dissociation of pre-adsorbed O2 into oxygen adatoms to not only enable the propylene epoxide production, at about 167 K, but also open up a new partial oxidation pathway with oxygen adatoms to produce propanal at about 340 K. These results highlight interesting photo-thermo synergistic effects on surface chemistry of TiO2.
