Study On The Structure Regulation And Photocatalytic Activity Of TiO 2 Microbubbles And Their Magnetic Composites

Titanium dioxide(TiO2), as a promising n-type semiconductor photocatalyst, has received much attention and been applied for purification of waste waters because of its high efficiency, low cost, non-secondary pollution, and so forth. However, the current research and the hot point are still focused on the modification of TiO2 and means of microstructure modulation for improving photocatalytic activities. In this paper, based on one-dimension nano-structure, TiO2 microspheres was prepared. Firstly, then the magnetic composites was fabricated to solve the separating and recycling problem under external magnetic fields. And SiO2 and amorphous carbon was introduced as mid-layer for fabricating Fe3O4/Si O2/TiO2 nanotube(FST–NT) composites and Fe3O4/C/TiO2 nanotube(FCT–NT) composites. XRD, BET, UV-vis, FE-SEM, and VSM were carried out to investigate physical properties of the sample. A photocatalytic degradation reaction model of phenol solution taken under a simulant solar ray, the photocatalytic performance of the FST–NT and FCT–NT composites were also evaluated with compared to commercial P25 and homemade TiO2 particles.TiO2 nanotube microspheres(TNTM) was anatase phase by a two-pot hydrothermal method, and Ti O2 nanorod microspheres(TNRM) was ascribe to single rutile phase with a diameter of 1.5 um by a one-pot hydrothermal method. TNRM has a complete nanorod structure with a width of 6–9 nm. The band energy of TNTM and TNRM were both reduced, and the photocatalytic activities were improved.Fe3O4 nanoparticle exhibit more regular spherical shape, and the SiO2 layer was amorphous type of Fe3O4/SiO2 particles and prepared by a modified st?ber method, then the FST–NT was prepared by a two-pot hydrothermal method; Fe3O4/C particles were by a hydrothermal method, and the most appropriate concentration of glucose was 0.05 g mL–1, then the FCT(s)–NT composites were fabricated via a sol-gel method and a alkali hydrothermal process, FCT(s)–NT composites have a complete structure with a diameter of about 8–10 nm, and possess a high surface area.Compared with commercial P25, pure TiO2, and TNTM sample, FST–NT, FCT(h)–NT, and FCT(s)–NT composites all exhibit high visible light intensity, and light absorption was expanded to visible light region. The above three catalysts exhibited enhanced photocatalytic activities under Xenon lamp irradiation, the conversion of FST–NT and FCT(s)–NT composites were both improved to 80%.The as-prepared Fe3O4 and three hierarchical TiO2 composites all show excellent magnetic behavior, and weak ferromagnetic property. The highest saturation magnetization Ms of above hierarchical TiO2 composites was 15 emu g–1.