A novel magnetic microsphere was prepared by simple microemulsion polymerization for protein drug delivery systems. The Fe₃O₄ magnetic nanoparticles were successfully encapsulated in chitosan microspheres, which endowed the chitosan microspheres with good magnetism. The drug loading performance results indicated that the prepared magnetic chitosan microspheres exhibited a superior drug loading capacity, and the drug loading amount reached 947.01 mg g⁻¹. Furthermore, the magnetic chitosan microspheres also showed a higher drug release rate (87.8%) and evident sustained-release performance in vitro. The magnetic microsphere carrier will be widely used in the biomedical field as a promising drug carrier.

A highly-efficient graphitic carbon nitride (g-C₃N₄) photocatalyst for visible light photodegradation of rhodamine B (RhB) and methyl orange (MO) simulating dyeing wastewater was synthesized by the thermal polycondensation of melamine. The photocatalysts were characterized by TG-DTG-DSC, XRD, EA, XPS, FT-IR, SEM, TEM, BET, PL and UV-vis DRS. The results showed that the photocatalytic performance of g-C₃N₄ at a higher calcination temperature was significantly enhanced, and its photocatalytic activities for the photodegradation of RhB and MO were remarkably improved by 64.91% and 41.83%, respectively, which was mainly attributed to the satisfactory crystallinity, stable graphene-like structure, large surface area, and excellent optical properties. It was found that •O₂⁻ radicals and •OH radicals were the main active species for the photodegradation process by the free radicals trapping experiments and ESR analysis. The photodegradation mechanism of g-C₃N₄ was proposed predicated using the characterization results.

The sulfonated magnetic SiO₂ microsphere solid acid catalysts were prepared by the impregnation and grafting methods with iron oxide magnetic nanoparticles (Fe₃O₄ MNPs) as the magnetic cores. The catalytic properties of the magnetic SiO₂ solid acid catalyst were studied in detail. The characterization results showed that the SiO₂ was successfully coated on the Fe₃O₄ MNPs. Compared with the grafting method, impregnated solid acid exhibits higher catalytic performance, which reached an esterification rate of up to 99.00% when the reaction temperature was 105 °C, the molar ratio of n-butanol/adipic acid was 3:1, and the ratio of the catalyst (the mass of magnetic solid acid) to liquids (the total volume of n-butanol and adipic acid) was 2.95%. The magnetic solid acid exhibited great separation ability and reusability. After six times of recycle, the conversion of the grafted magnetic solid acid still attained 85.61% compared with that of the impregnated magnetic solid acid, which reduced to 81.35%, holding great potential for green chemical processes.