Preparation and visible-light photocatalytic activity of ag-loaded TiO2@Y2O3 hollow microspheres with double-shell structure

Removal of pollutants through photocatalysis, adsorption, and electrochemical sensing by a unique plasmonic structure of palladium and strontium oxide nanoparticles sandwiched between 2D nanolayers

The redesigned engineering building of nanocomposite (NCP) depends on metal oxides of palladium oxide (PdO) nanoparticles (NPs) conjugate with the n-type semiconductor of strontium oxide (SrO) NPs on the electron carrier surface of graphene oxide (GO) and reduce graphene oxide (rGO) nanosheet is the main target of the current work. The low efficiency of PdO (n-type) and SrO (p-type) gave an overview of the increasing generation electron efficiency via building the ohmic area on the GO and rGO surface using the Z-scheme mechanism. The efficiency of the NCP surface for destroying organic pollutants such as mixed dyes of Rhodamine B and methylene blue (RhB/MB), as against insecticides like imidacloprid, and the removal of heavy metals such as chromium ions was studied. The production of clean water against pollutants materials was investigated through adsorption and photocatalytic processes, electrochemical, and spectroscopy methods to detect the activity of NCP. The rate constant of the adsorption pollutants is 0.1776 min-1 (MB), 0.3489 min-1 (RhB), 0.3627 min-1 (imidacloprid), and 0.5729 min-1 (Cr3+). The photocatalytic rate recorded at 0.01218 min-1 (MB), 0.0096 min-1 (RhB), appeared degradation rate at 0.0086 min-1 (imidacloprid), 0.0019 min-1 (Cr6+), and 0.0471 min-1 (Cr3+). The adsorption and photocatalytic efficiency of nanocatalyst (NCP) was calculated at 91% (RhB), 93% (MB), 73% (imidacloprid), 63% (Cr3+), while the photocatalytic efficiency is 63% (RhB), 94% (MB), 86% (imidacloprid), 33% (Cr3+). The recyclability of NCP was tested for five cycles, and the efficiency was discovered at 55% after the fifth cycle. The cytotoxicity of NCP was studied to detect the safety of the fabricated materials. The study validates that the fabricated nanocomposite exhibits great potential as an innovative material for producing clean water.

Novel Z-scheme MgFe2O4/Bi2WO6 heterojunction for efficient photocatalytic degradation of tetracycline hydrochloride: Mechanistic insight, degradation pathways and density functional theory calculations

In this study, a new Z-scheme MgFe2O4/Bi2WO6 heterojunction was successfully prepared by hydrothermal and wet ball milling process. The results of the study showed that after 90 min of visible light exposure, the photocatalytic degradation of tetracycline hydrochloride (TCH) by 25%-MgFe2O4/Bi2WO6 heterojunction was as high as 95.82%, and the highest photocatalytic rate (0.0281 min-1) was 4.61 and 3.43 times higher than that of pure Bi2WO6 (0.0061 min-1) and MgFe2O4 (0.0082 min-1), respectively. Furthermore, spin-polarized density functional theory (DFT) calculations were performed to provide additional evidence of the presence of a Z-scheme charge transfer mechanism between MgFe2O4 and Bi2WO6. We investigated the effects of initial TCH concentration, pH, coexisting ions and different water sources on the efficiency of photocatalytic degradation of TCH in composite samples. The recovery experiments demonstrated that the MgFe2O4/Bi2WO6 composites had good stability and repeatability. A series of experimental results showed that 25%-MgFe2O4/Bi2WO6 had a larger specific surface area, better ultraviolet and visible absorbance, superior charge transfer and higher efficiency of photogenerated electron-hole pair separation. This paper provides new ideas for the design and preparation of new Z-scheme heterojunctions and has great prospects for practical applications in the field of wastewater treatment.

Enhancing the photoinduced via a novel nano-combination of terbium oxide and nickel oxide on graphene oxide surface: Cytotoxicity and water treatment

The target is a novel nano-combination membrane (NCM) via Terbium oxide nanoparticles (Tb₂O₃ NPs) and nickel oxide (NiO NPs) which integrates on the graphene oxide (GO) surface. The NCM is characterized by different tools such as X-ray diffraction (XRD), UV-visible spectrophotometer (UV-vis), and Scanning electron microscopy (SEM)for removing organic pollutants. The precipitation method has been applied for fabricating the selected metal oxides (MOs), where the terbium chloride and nickel chloride are used as precursors for fabricating the metal oxides (MOs) NPs that formed with potassium hydroxide in the solution. The photocatalytic activity of fabricated NCM has been noticed with the quenching of mixed Rhodamine B (RhB) and methyl orange (MO) dyes at various times for water treatment. UV-vis spectra confirmed the excellent efficiency against organic pollution degradation. After exposure to the light for 100 min, the photodegradation efficacy of MB and RhB appeared at 46.88 % and 16.4 %, with GO@Tb2O3, by GO@Tb2O3.NiO the efficiency was 54.8 % and 32.3 % after 100 min, while GO@NiO has degradation efficiency at 43 % and 17.3 % for MB and RhB respectively. The cytotoxicity of NCM is detected with hepatocellular carcinoma (HepG2) and breast adenocarcinoma (MCF-7), the result illustrated that the fabricated NCM does not affect the cancer cells with the 10 µL, but with the higher concentration of 100 µL, the cell lysis was observed. The results of photocatalytic and cytotoxicity are recommended using these fabricated NCM in water treatment.

Synthesizing Ag2Ox(3 wt%)-loaded ZnFe2O4 photocatalysts for efficiently saving polluted aquatic ecosystems

Herein, we report an Ag2Ox (3 wt%)-loaded ZnFe2O4 photocatalysts synthesized by co-precipitation and incipient wet impregnation approach for acetamiprid degradation, antibacterial, antioxidant, and toxicity assay. Initially, bare ZnFe2O4 nanostructures were made through a simple co-precipitation method. In the second step, 3 wt% of various transition metal oxides (CuOx, ZrOx, and Ag2Ox) were embedded on the surface of ZnFe2O4 photocatalysts via a wet impregnation method. Further, the prepared photocatalysts were systematically characterized using XRD, FTIR, FE-SEM, BET, HRTEM, and XPS analysis. The optimum Ag2Ox (3 wt%)-loaded ZnFe2O4 photocatalysts revealed higher degradation efficiencies for acetamiprid under sunlight irradiation. Additionally, the Ag2Ox (3 wt%)-loaded ZnFe2O4 photocatalysts showed more effective antioxidant and antibacterial activity than blank and bare ZnFe2O4 nanomaterials. The enriched catalytic efficiency can be accredited to the 3 wt% of Ag2Ox NPs loaded on ZnFe2O4 nanomaterials, possibly due to the boosted transport properties of the electron-hole pairs. This study will provide a new avenue for the development of simple and effective photocatalysts for efficiently saving polluted aquatic ecosystems.

Preparation of Y2O3/TiO2-Loaded Polyester Fabric and Its Photocatalytic Properties under Visible Light Irradiation

In this study, Y2O3/TiO2-loaded polyester fabric was prepared to improve the catalytic activity of the TiO2 and to increase its reuse efficiency. The samples were systematically characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FT-IR). Furthermore, the degradation performance of methyl orange in the presence of simulated visible light irradiation was also investigated. The results showed that the TiO2 in the Y2O3/TiO2 composite photocatalyst was suitably anatase. In addition, Y2O3/TiO2-loaded polyester fabric had higher photocatalytic performance than that of pure polyester fabric under visible light and the degradation rate reached 83% after 120 min of light exposure but remained above 50% after repeated exposure (three times). Compared to the pure polyester fabric, Y2O3/TiO2-loaded polyester fabric had self-cleaning effects in methyl blue and soy sauce solutions under visible light.