Preparation And Properties Of Titania-based Hollow Microspheres Photocatalysts

Photocatalytic degradation has a number of advantages, such as low energy consumption, mild reaction conditions and process, the high reaction rate, the non-selectivity to substrate, complete mineralization to generate inorganic small molecules and other nontoxic substances, etc. Therefore, in the past few decades research and application about photocatalysis has been widely carried out. Wherein, TiO₂ has advantages of nontoxicity, high chemical inertness, good light stability, low cost, high catalytic activity. ZnO has characteristics with low cost, wide sources, nontoxicity and pollution-free. But recombination rate of their photo-generated carrier is too fast, not being able to efficiently degrading organic pollutants, which has greatly limited the application. In this paper, the work is carried out to reduce photo-generated carriers' recombination rate of TiO₂-based materials. The main contents are as follows:?1? ?001? facets exposed bird's nest-like TiO₂ hollow microspheres were prepared via one-step solvothermal method. The physical structure of the catalysts was characterized by SEM, TEM, XRD, BET, etc. The chemical structure of the catalysts was characterized by EDS, XPS. The optical properties of the catalysts were characterized by UV-vis DRS, PL, TOC and other means. Methylene blue ?MB? was used as a target pollutant. Photocatalytic degradation results show that the solvothermal temperature 180?, calcination temperature 500?, the photocatalyst has the highest photocatalytic activity in the photocatalytic degradation of MB. In addition, the photocatalyst can be easily recovered by filtration or sedimentation and be reused.?2? TiO₂ as a substrate, ZnO as a modifier, TiO₂/ZnO composite hollow microspheres were fabricated via an one-step hydrothermal method. The physical structure of the catalysts was characterized by SEM, TEM, XRD, BET, etc. The chemical structure of the catalysts was characterized by means of XPS. The optical properties of the catalysts were characterized by UV-vis DRS, PL, TOC and so on. The catalysts were applied to photocatalytic degradation of 2,4-dinitrophenol ?2,4-DNP?, a typical organic pollutants. With 0.2 g/L of catalyst dosage,10 mg/L of substrate concentration,10 cm of illumination distance, the percentage degradation to 2,4-DNP is the highest. The as-prepared composite photocatalyst is stable and easy to recycle.