A novel SiCN@TiO2 core-shell ceramic microspheres derived from a polymeric precursor

A novel core-shell ceramic microspheres, composed of a SiCN inner core and TiO2 nanoparticles outer shell, were prepared via emulsion technique and polymer-derived ceramics (PDCs) method. The forming process of SiCN@TiO2 core-shell ceramic microspheres were controlled by adjusting the ratio of raw material, curing temperature and pyrolysis temperature. The morphology, chemical composition and phase transformation were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). PVSZ@TiO2 microspheres with good spherical structure and uniform-dispersed TiO2 surface were fabricated at 200 °C with raw material ratio of 25%. After pyrolyzed at 1400 °C, the obtained SiCN@TiO2 core-shell ceramic microspheres retained spherical structure. The XRD showed that the products were mainly composed of rutile TiO2, SiC and Si3N4 crystalline phase, which were generated by polyvinylsilazane.