Magnetic layered double hydroxide supported gold nanoparticles as a robust and recyclable catalyst for the reduction of 4- nitrophenol and oxidation of alkenes and benzyl alcohols

In this study, we report the synthesis of a novel magnetic nanocomposite, Fe₃O₄@SiO₂@MgAl-LDH@Au, as an efficient and environmentally benign catalyst for both reduction and oxidation reactions. The mesoporous nanocomposite was well-identified using FT-IR, XRD, EDX, TEM, TGA, FESEM, VSM, BET and XPS analyses. Its catalytic performance was first evaluated in the reduction of 4-nitrophenol to 4-aminophenol, monitored by UV-Vis spectroscopy, which confirmed its remarkable activity in the presence of sodium borohydride as a reducing agent. Furthermore, the catalyst was tested in the oxidation of organic substrates, exhibiting moderate to high conversion and selectivity for benzyl alcohols and alkenes. Notably, Fe₃O₄@SiO₂@MgAl-LDH@Au demonstrated excellent recoverability and reusability over multiple cycles, with only a slight decrease in catalytic activity.