Fe₃O₄ nanoparticle decorated novel magnetic metal oxide microcomposites for the catalytic degradation of 4-nitrophenol for wastewater cleaning applications

Co₃O_4, NiO and ZnO microparticles were decorated with Fe₃O₄ nanoparticles where novel Co₃O₄@Fe₃O₄, NiO@Fe₃O₄ and ZnO@Fe₃O₄ microcomposites were obtained with significant magnetic properties. Decorating microparticles with Fe₃O₄ nanoparticles helped us to obtain microcomposites with outstanding magnetic characteristics, since Fe₃O₄ nanoparticles were decorated on the upper shell of the microstructures where the magnetic characteristics of the composites were not suppressed, and good catalytic performance was obtained. SEM was used to assess the physical morphology of the microparticles which indicate that microparticles were in flower or ball-like shape. Magnetic properties were checked using VSM which revealed that magnetic composites are in ferromagnetic characteristics. Optic characteristics of the particles were checked by UV–Vis spectrometry to assess bandgap energies which indicate that doping microparticles with Fe₃O₄ slightly alters the bandgap energies of microparticles. The catalytic role of microparticles and microcomposites for the catalytic reduction of 4-nitrophenol to 4-aminophenol was studied.