Preparation And Photocatalytic Properties Of Titanium Dioxide, Tin Dioxide And Barium Titanate Nanocomposites

In recent years,water pollution has become the difficult problem and challenge of the global development.The considerable proportion of water pollutants is organic pollutants,which comes mainly from industrial waste-water,sewage,food processing,medicine,pesticide production and etc.It is difficult to be decomposed because of the waste water containing high concentration of organic pollutants such as polycyclic aromatic hydrocarbon,phenols,halogenated hydrocarbon and so on.Chemical method is one of the most effective ways for wastewater treatment,the harmful ingredients of water will be transformed into innoxious substance by using redox reaction.In the aspect of dealing with organic waste water,nano-semiconductor photocatalytic materials have become the research focus owing to their high efficiency,low cost and no secondary pollution in resent years.However,the currently used semiconductor materials such as TiO₂,SnO₂ and SrTiO₃ always have disadvantages of photogenerated carriers recombination caused by their single-phase structure,the wider of forbidden band gap,narrow absorbing range?about 5% ultraviolet absorber?,which limits their widely applications.As known,the hybrid of TiO₂,SnO₂ and SrTiO₃ can broaden their light abstraction width effectively.Herein,we synthesized the heteronanocrystals of TiO₂/Cr2O₃,TiO₂/Fe2O₃,SnO₂/Cr2O₃,SnO₂/Fe2O₃,SrTiO₃/Cr2O₃ and SrTiO₃/Fe2O₃ successfully,and investigated their photocatalysis properties.1.TiO₂ nanobelts?NBs?have been synthesized successfully by using hydrothermal method.The XRD confirmed that the as-prepared TiO₂ NBs consisted of anatase and rutile phases,and gave priority to anatase phase.TEM images showed that the diameter of TiO₂ nanobelts was about 100 nm to 200 nm.TiO₂/Cr2O₃ and TiO₂/Fe2O₃ were synthesized based on the intersurface redox reaction at room temperature.The photocatalytic activity of TiO₂,TiO₂/Cr2O₃ and TiO₂/Fe2O₃ were evaluated by investigation the photocatalytic degradation process of methylene blue.Under xenon lamp?50 W?for five hours,the experimental data showed that thedegradation rate of TiO₂,TiO₂/Cr2O₃ and TiO₂/Fe2O₃ were 56.7%,79.0% and 68.3%,respectively.The higher photocatalytic performance of as-prepared heteronanocrystals mainly attributed to the improvement of the electronic transmission efficiency and electronic-hole separation efficiency.2.Using commercial nano SnO₂,SnO₂/Cr2O₃ and SnO₂/Fe2O₃ were fabricated by using interface redox reaction methods.The as-prepared heteronanocrystals were characterized by means of XRD,SEM,TEM,EDS and HRTEM etc.TEM images showed that the surface of SnO₂ was covered by nanoparticles of Cr2O₃ and Fe2O₃,respectively.The photocatalytic activity of as-synthesized heteronanocrystals was investigated by the experiments of methylene blue.Under xenon lamp?50 W?for five hours,the experimental data showed that the degradation rate of SnO₂,SnO₂/Cr2O₃ and SnO₂/Fe2O₃ were 58.6%,69.4% and 86.9%,respectively.Compared with nano SnO₂,heterojunction materials have better photocatalytic performance.3.Taking commercial P25 and Sr?OH?2·8H2O act as reactants,the precursor of SrTiO₃ nanoparticles has been synthesized successfully by using hydrothermal method.Then SrTiO₃/Cr2O₃ and SrTiO₃/Fe2O₃ were fabricated by using interface redox reaction methods.The as-synthesized heteronanocrystals were characterized by means of XRD,SEM,TEM and HRTEM etc.The photocatalytic activity of SrTiO₃,SrTiO₃/Cr2O₃ and SrTiO₃/Fe2O₃ were evaluated by investigation the photocatalytic degradation process of methylene blue.Under xenon lamp?50 W?for five hours,the experimental data showed that the degradation rate of SrTiO₃,SrTiO₃/Cr2O₃ and SrTiO₃/Fe2O₃ were 62.2%,69.5% and 75.4%,respectively.The higher photocatalytic performance of as-prepared heteronanocrystals mainly attributed to the improvement of the electronic transmission efficiency and electronic-hole separation efficiency.To sum up,the semiconductor heterojunction materials were synthesized by intersurface redox reaction method,which possesses good performance in photocatalytic degradation.The synthestic method is simple and easy to popularize.