Investigation on the coating modification effect of nano-SiO2 particles on nano-TiO2 particles

• Published in: Materials research express 2019-04, Vol.6 (7)
• Main Authors: Du, Bin, Chen, Feng, Luo, Rubai, Zhou, Shisheng, Wu, Zhengneng, Li, Jinglei
• Format: Article
• Language: English
• Subjects: coating; nanoparticles; sol-gel method; surface modification
• ISSN: 2053-1591
• DOI: 10.1088/2053-1591/ab192d

TiO2 has received significant scientific attention as a highly operative, stable, and low-cost photocatalyst. However, the decomposition of organic matrices due to its photocatalytic action is considered to be one of the main drawbacks of TiO2 nanoparticles in its applications in inks. To overcome this problem, this study aims to coat the surface of the nano-TiO2 particles with a layer of nano-SiO2 particles through a sol-gel method. The nano-TiO2 powder was dispersed by polyvinylpyrrolidone (PVP) and 4-vinylpyridine (4VP). The effects of different concentrations of PVP and 4VP, molar ratios of silicon to titanium, and ammonia water dosage on the properties of the composite particles were investigated. Scanning electron microscopy (SEM) analysis showed that the coating effect is best when the PVP had a mass of 2 g, the 4VP had a volume of 2 ml, the ratio of titanium to silicon was 1:2, and the amount of ammonia was 5 ml. The transmission electron microscopy (TEM) images show that titania particles were successfully coated on the surface of nano-TiO2. The x-ray diffraction (XRD) patterns showed no change in the crystal structure of nano-TiO2 before and after coating with nano-SiO2. Comparing the Fourier-transform infrared (FT-IR) and x-ray photoelectron (XPS) spectra, it was found that the Ti-O-Si bond is present in the nano-TiO2/SiO2 composite particles, and the Si element is present in the TiO2 crystal in the form of Ti-O-Si. These results indicate that the nano-SiO2 was coated on the surface of the nano-TiO2 successfully, and the ultraviolet (UV) resistance of pure nano-TiO2 is effectively improved.