Inbasekaran Muthuvel

Novel silver encapsulated nanocomposite zinc oxide/iron tetra-poly-vanadate (Ag-ZnO/Fe₂V₄O₁₃) was synthesized with various wt% of silver (1.0–2.5 wt% of Ag) by cost-effective photo-deposition method under the irradiation of ultraviolet-A (UV-A) light. The nanostructure of the Ag-ZnO/Fe₂V₄O₁₃ was explored by various characterization techniques. The surface functionalities were confirmed by Fourier transform infrared spectra and the crystalline nature of the material was revealed by X-ray diffraction patterns. Furthermore, the surface morphology and the optical properties of the composites were analyzed by scanning electron microscopy, energy dispersive X-ray–elemental color mapping (ECM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible diffuse reflectance spectroscopy and photoluminescence. The crystallite size of Ag-ZnO/Fe₂V₄O₁₃ was 28.5 nm which was consistent with HRTEM analysis. The photocatalytic activity was tested against aqueous methyl orange degradation under UV-A light irradiation. In all five runs, the stability of the catalyst was confirmed by reusability measurements and almost 98% of degradation was achieved. A suitable degradation pathway was proposed based on intermediates obtained during the degradation analyzed by gas chromatography–mass spectrometry. Trapping experiments confirmed that the superoxide radical anion (O₂^•−) was considered as the most active species for this degradation process. Complete mineralization was confirmed by the measurements of chemical oxygen demand.

Novel Ag encapsulated nanocompositesZnO/Fe₂V₄O₁₃ (AZF) were synthesized with various wt% of the silver (from 1.0 to 2.5 wt% of Ag) by photo-deposition method using UV-A light. The nanostructure of the AZF was explored by various characterization techniques. Surface functional group was confirmed by FT-IR spectra, the crystalline nature of the material revealed by XRD patterns. Furthermore, surface morphology and optical properties of the composites were analyzed by SEM, HR-TEM UV-DRS and PL respectively. The photoactivity was tested against Methyl Orange (MO) degradation under UV light. The stability of the catalyst was confirmed by reusability measurements. Suitable degradation pathway was proposed based on intermediates obtained during degradation analyzed by GC-MS. Trapping experiments confirmed that super oxide radical anion (O₂^·–) has been consider as a most active species for this degradation process. Mineralization is confirmed by measurements of chemical oxygen demand (COD).

In this study, we synthesized CeVO₄/ZnO nanoheterojunction photocatalyst through hydrothermal-precipitation method. The prepared photocatalyst was characterized by Fourier transform infrared analysis (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) with elemental color mapping (ECM), high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) pattern, UV-vis diffuse reflection spectroscopy (UV-vis-DRS), BET, and photoluminescence (PL) spectroscopy. The BET surface area of CeVO₄/ZnO is 10.50 m²/g. The photocatalytic activity of CeVO₄/ZnO nanoheterojunction under solar light was investigated for the degradation of Reactive Orange 4 (RO 4). CeVO₄/ZnO has been found to be more effective for mineralization of RO 4 than the prepared ZnO at neutral pH. The addition of TBA (^•OH scavenger) contributes a significant decrease in the photodegradation efficiently of the catalyst. Chemical oxygen demand (COD) measurements confirmed the complete mineralization of RO 4. In addition, it found that the photocatalyst was stable and reusable. Graphical abstract