Synthesis, Doping And Performance Study Of Micro-nano ZnO, SnO₂ And CeO₂ Materials

Metal oxide micro-nano materials such as ZnO,SnO₂and CeO₂have wide applications in catalysis,gas sensing elements and light energy storage due to their excellent physical and chemical properties.In this dissertation,ZnO,SnO₂and CeO₂micro-nano materials are used as research objects.Three oxide micro-nano materials with novel morphology are prepared by using hydrothermal method,and the formation mechanism of the oxides is discussed.Finally,they were doped and subjected to a series of characterizations.These three micro-nano materials and their doping were used as photocatalysts to degrade organic pollutants?such as Rhodamine B?Rh B?solution and methyl orange?MO?Solution?.?1?The main contents of this paper include the following aspects:Spherical ZnO micro/nano materials were successfully prepared by hydrothermal method,and a series of different concentrations of Ce were doped on them.The products were characterized and analyzed by XRD,SEM,EDS,XPS,DRS,which proved that Ce was incorporated into the spherical ZnO.Photocatalytic degradation of Rh B under visible light was used to compare the photocatalytic activity of single-flowered spherical ZnO and Ce-doped flower-shaped ZnO.We propose a possible growth mechanism of spherical ZnO,and explain the reaction process of Ce-doped spherical ZnO.The doped ZnO obtained by irradiating the Rh B aqueous solution with visible light showed better photocatalytic performance,and the optimal doping amount of Ce was determined.?2?Hexagonal ZnO structure was obtained by hydrothermal at 120?for 6 h.We have proposed a possible formation mechanism for this.After doping with appropriate amount of graphene oxide?GO?,the photodegradation rate of Rh B reached 90.8%in 60 min.It was found that the incorporation of GO can reduce the recombination of photo-generated electron-hole pairs,thereby significantly improving its photocatalytic ability.?3?The SnO₂micro/nanostructure was synthesized by hydrothermal method.The obtained SnO₂micro/nano structure is doped with g-C₃N₄.The SnO₂doped with g-C₃N₄under visible light irradiation showed higher photocatalytic activity for the degradation of Rh B,and the optimal degradation of g-C₃N₄doped SnO₂was determined.?4?A novel spherical CeO₂with a particle diameter of about 2 um was prepared.By incorporating GO,we performed a series of characterization tests to confirm that GO was indeed doped.In addition,under visible light irradiation,the resulting doped products exhibited excellent photocatalytic activity,and the degradation of MO was greatly improved compared to pure CeO₂.At the same time we explained the mechanism of GO/CeO₂photocatalytic degradation of MO.