Enhanced photocatalytic degradation of amoxicillin using a spinning disc photocatalytic reactor (SDPR) with a novel Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure

Antibiotics are resistant compounds with low biological degradation that generally cannot be removed by conventional wastewater treatment processes. The use of yolk-shell nanostructures in spinning disc photocatalytic reactor (SDPR) enhances the removal efficiency due to their high surface-to-volume ratio and increased interaction between catalyst particles and reactants. The purpose of this study is to investigate the SDPR equipped to Fe3O4@void@CuO/ZnO yolk-shell thin film nanostructure (FCZ YS) in the presence of visible light illumination in the photocatalytic degradation of amoxicillin (AMX) from aqueous solutions. Stober, co-precipitation, and self-transformation methods were used for the synthesis of FCZ YS thin film nanostructure and the physical and chemical characteristics of the catalyst were analyzed by XRD, VSM,, EDX, FESEM, TEM, AFM, BET, contact angle (CA), and DRS. Then, the effect of different parameters including pH (3-11), initial concentration of AMX (10-50 mg/L), flow rate (10-25 mL/s) and rotational speed (100-400 rpm) at different times in the photocatalytic degradation of AMX were studied. The obtained results indicated that the highest degradation efficiency of 97.6% and constant reaction rate of AMX were obtained under LED visible light illumination and optimal conditions of pH = 5, initial AMX concentration of 30 mg/L, solution flow rate of 15 mL/s, rotational speed of 300 rpm and illumination time of 80 min. The durability and reusability of the nanostructure were tested, that after 5 runs had a suitable degradation rate. Considering the appropriate efficiency of amoxicillin degradation by FCZ YS nanostructure, the use of Fe3O4@void@CuO/ZnO thin film in SDPR is suggested in water and wastewater treatment processes.

Enhancement of the catalytic activity of Suzuki coupling reactions by reduction of modified carriers and promotion of Pd/H2-PrxOy surface electron transfer

Pd/H2-PrxOy nanotubes were prepared by electrostatic spinning, high-temperature calcination and modified deposition–precipitation method, and exhibited high catalytic performance for Suzuki coupling reaction under mild conditions.

Advances in Magnetic Nanoparticles-Supported Palladium Complexes for Coupling Reactions

Carbon‒carbon (C‒C) and carbon‒heteroatom (C‒X) bonds that form via transition-metal-catalyzed processes have been extensively used in the organic synthesis and preparation of natural products and important compounds such as heterocycles, biologically active molecules, and dendrimers. Among the most significant catalysts, magnetic nanoparticles-supported palladium complexes are very effective, versatile, and heterogeneous catalysts for a wide range of C‒C and C‒X coupling reactions due to their reusability, thermal stability, and excellent catalytic performance. In this review, recent advances to develop magnetic nanoparticles supported palladium complexes, including their preparation, characterization, catalytic application, and reusability in the formation of both C‒C and C‒X bonds, by authors such as Sonogashira, Heck, Suzuki‒Miyaura, and Stille, and a few examples concerning N-arylation, S-arylation, and Csp2-P coupling reactions are discussed.

Implantation of Fe3O4 Nanoparticles in Shells of Au@m-SiO2 Yolk@Shell Nanocatalysts with Both Improved Recyclability and Catalytic Activity

Multifunctional nanocatalysts of Au@Fe₃O₄/m-SiO₂ yolk@shell hybrids had been developed through a template-assisted synthesis, where Fe₃O₄ nanoparticles (∼12 nm) and m-SiO₂ shells were sequentially assembled on surfaces of Au/SiO₂ core/shell templates, followed by selective etching of the inner SiO₂ cores, leading to the formation of Au@Fe₃O₄/m-SiO₂ yolk@shell hybrids. The Fe₃O₄ nanoparticles were implanted in the inner surfaces of m-SiO₂ shells with partially exposed surfaces to the inner cavity. The novel design not only ensures a high surface area (540.0 m²/g) and saturation magnetization (48.6 emu/g) of the hybrids but also enables interaction between Au and Fe₃O₄ nanoparticles. Catalytic tests toward the reduction of 4-nitrophenol in the presence of NaBH₄ indicated that Au@Fe₃O₄/m-SiO₂ yolk@shell nanocatalysts not only showed high stability and recyclability but also maintained improved catalytic activity as a result of the synergetic effect resulting from Au and Fe₃O₄ interactions.

Fe3O4@PANI Hybrid Shell as a Multifunctional Support for Au Nanocatalysts with a Remarkably Improved Catalytic Performance

Au@Fe₃O₄@PANI hybrid shells with controllable polyaniline (PANI) coatings as advanced supported catalysts have been fabricated. Specifically, Fe₃O₄ and Au nanoparticles were assembled on SiO₂ templates, followed by conducting polymer PANI coating, leading to the formation of Au@Fe₃O₄@PANI hybrid shells after the template removal. The resultant supported Au nanocatalysts not only maintain hollow structures but also possess high saturation magnetization (65.46 emu/g). Catalytic tests toward the reduction of 4-nitrophenol in the presence of NaBH₄ indicate that PANI and Fe₃O₄ not only endow high stability and recyclability but also can largely improve the catalytic activity of Au nanoparticles because of their synergetic effects. It is believed that Fe₃O₄@PANI hybrid shells can be regarded as multifunctional supports for noble metal nanocatalysts with a remarkably improved catalytic performance.