Fe3O4@PS@PAMAM-Ag Magnetic Nanocatalysts and Their Recoverable Catalytic Ability

Deciphering the catalytic activity of nickel anchored on Fe3O4@SiO2@3-CPMS@L as a magnetically recoverable nanocatalyst for the efficacious reduction of 4-nitrophenol, nitrobenzene, and methyl orange

In this paper, a versatile heterogeneous nanocatalyst was fabricated employing a self-assembly technique. To commence, Fe3O4 MNPs were coated with a thin layer of SiO2 using the stobbers method. Subsequently, the surface was further functionalized with 3-CPMS, followed by a reaction with a Schiff base. Finally, nickel NPs were deposited on the surface through in situ deposition, forming the Fe3O4@SiO2@3-CPMS@L-Ni magnetic nanocatalyst. The architecture of this magnetic nanocatalyst was meticulously characterized through an array of sophisticated techniques: XRD, FT-IR, SEM, TEM, BET and VSM. The XRD diffraction pattern confirmed the presence of Fe3O4 MNPs, SiO2, and Ni peaks, providing evidence for successful synthesis. Moreover, the successful functionalization with a Schiff base was demonstrated by the presence of an azomethane peak in the FTIR spectra of the synthesized nanocatalyst. The fabricated nanocatalyst was adeptly utilized for the reduction of 4-NP, NB, and MO demonstrating a remarkably elevated rate of catalytic efficacy. Moreover, this catalyst was effortlessly retrievable through the application of an external magnet, and it maintained its catalytic prowess across at least six consecutive cycles. The utilization of water as an environmentally friendly solvent, coupled with the utilization of abundant and cost-effective nickel catalyst instead of the costly Pd or Pt catalysts, along with the successful recovery and scalability of the catalyst, render this method highly advantageous from both environmental and economic perspectives for the reduction of 4-NP, NB, and MO.

Synergistic effect of silver NPs immobilized on Fe3O4@L-proline magnetic nanocomposite toward the photocatalytic degradation of Victoria blue and reduction of organic pollutants

The surface of magnetite (Fe₃O₄) nanoparticles was subject to modification through the incorporation of L-proline (LP) by simple co-precipitation method in which silver nanoparticles were deposited by in situ method, thereby yielding the Fe₃O₄@LP-Ag nanocatalyst. The fabricated nanocatalyst was characterized using an array of techniques including Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), Brunauer-Emmett-Teller (BET), and UV-Vis spectroscopy. The results evince that the immobilization of LP on the Fe₃O₄ magnetic support facilitated the dispersion and stabilization of Ag NPs. The SPION@LP-Ag nanophotocatalyst exhibited exceptional catalytic efficiency facilitating the reduction of MO, MB, p-NP, p-NA, NB, and CR in the presence of NaBH₄. The rate constants obtained from the pseudo-first-order equation were 0.78, 0.41, 0.34, 0.27, 0.45, 0.44, and 0.34 min^-1 for CR, p-NP, NB, MB, MO, and p-NA, respectively. Additionally, the Langmuir-Hinshelwood model was deemed the most probable mechanism for catalytic reduction. The novelty of this study lies in the use of L-proline immobilized on Fe₃O₄ MNPs as a stabilizing agent for the in-situ deposition of silver nanoparticles, resulting in the synthesis of Fe₃O₄@LP-Ag nanocatalyst. This nanocatalyst exhibits high catalytic efficacy for the reduction of multiple organic pollutants and azo dyes, which can be attributed to the synergistic effects between the magnetic support and the catalytic activity of the silver nanoparticles. The easy recyclability and low cost of the Fe₃O₄@LP-Ag nanocatalyst further enhance its potential application in environmental remediation.

Catalytic Neutralization of Water Pollutants Mediated by Dendritic Polymers

Radially polymerized dendritic compounds are nowadays an established polymer category next to their linear, branched, and cross-linked counterparts. Their uncommon tree-like architecture is characterized by adjustable internal cavities and external groups. They are therefore exceptional absorbents and this attainment of high concentrations in their interior renders them ideal reaction media. In this framework, they are applied in many environmentally benign implementations. One of the most important among them is water purification through pollutant decomposition. Simple and composite catalysts and photo-catalysts containing dendritic polymers and applied in water remediation will be discussed jointly with some unconventional solutions and prospects.

Fabrication of Fe3O4@polydopamine@polyamidoamine core–shell nanocomposites and their application for Cu(ii) adsorption

Fe₃O₄@PDA@PAMAM nanocomposites were fabricated with a polydopamine assisted method, possessing excellent magnetic properties and high adsorption capacity for Cu(ii).

Multifunctional Fe3O4@nSiO2@mSiO2/Pr-Imi-NH2·Ag core–shell microspheres as highly efficient catalysts in the aqueous reduction of nitroarenes: improved catalytic activity and facile catalyst recovery

Core@shell nanoparticles with a superparamagnetic iron oxide core, a middle nonporous silica shell, and an outer organo functionalized mesoporous silica shell were synthesized and evaluated for immobilizing Ag nanoparticles.

Multifunctional Co(0.85)Se-Fe(3)O(4) nanocomposites: controlled synthesis and their enhanced performances for efficient hydrogenation of p-nitrophenol and adsorbents

A new kind of multifunctional Co0.85 Se-Fe3 O4 nanocomposites is synthesized by loading Fe3 O4 nanoparticles (NPs) with a size of about 5 nm on the surface of Co0.85 Se nanosheets under hydrothermal conditions without using any surfactant or structure-directing agents. The Co0.85 Se-Fe3 O4 nanocomposite exhibits remarkable catalytic performance for hydrogenation of p-nitrophenol (4-NP) at room temperature and good adsorption behavior for methylene blue trihydrate in water. This nanocomposite also shows a high specific surface area and magnetic separation capability for recyclable utilization. The enhanced performances both in catalysis and adsorption are better than either individual component of Co0.85 Se nanosheets or Fe3 O4 nanoparticles, demonstrating the possibility for designing new multifunctional nanocomposites with improved performances for catalysis, adsorbents, and other applications.

Morphologic control of Sb-rich Sb2Se3 to adjust its catalytic hydrogenation properties for p-nitrophenol

Sb-rich Sb₂Se₃ with hollow sphere morphology is an efficient catalyst for the hydrogenation of p-nitrophenol.