Based On The Semiconductor Sno < Sub > 2 < / Sub > Heterojunction In Preparation And Characterization Of Photocatalyst And Their Photocatalytic Performance Research

The discovery and application of semiconductor-basedphotocatalytic technology allow the solar energy to be effectivelytransferred to electrical energy and chemical energy. As an importantfunctional semi-conductor material, nano-structured SnO2arousedmuch interest and was extensively studied for its outstanding optical,electrical, catalytic, gas sensing, pressure sensing, heat sensing andmoisture sensing properties and so on. In recent years, many researchestried to research the photocatalytic properties and have done muchfruitful work on it. To the case of SnO2, it is short of size controllability andthe efficiency of utilizing sunlight, lots of efforts have being done toexplore more efficient SnO2-based photocatalysts.To solve the above problem, this thesis work is mainly focused onexploring effective and facile routes to fabricating novel visible lightresponse SnO2-based photocatalysts with high photocatalyticperformance and investigating the internal relationship between thephysicochemical properties, including size of the SnO2nanocrytals,composition, morphologies, and the photocatalytic performances. Thepresent thesis is composed of the following three parts:1.One-pot synthesis of size controllable SnO2nanoparticles and theresearch of their photocatalytic performance.A solvothermal method was used to synthesize SnO2nanoparticlesby using SnCl₂·2H2O and tert-butyl alcohol as the precursors. Differentkinds of solvents were modulated for obtaining size-controllable SnO2nanoparticles with good dispersion and uniform particle size. Theas-prepared samples were characterized by XRD, UV-vis, XPS, FESEMand TEM. Photoelectrocatalytic and photocatalytic performanceresults show that, the as-obtained SnO2nanoparticles exhibited muchhigher catalytic performance compared to the commercial SnO2in the purification of environment.2. Preparation of SnO2/SnS2heterojunction photocatalytic materials viaion-exchanging route and their photocatalytic propertiesIon exchanging route was utilized to fabricate SnS2/SnO2composites. Visible-light heterojunction SnO2/SnS2photocatalyst withhigh performance could be obtained via solvothermal treatment of themixture of as-prepared SnO2nanoparticles and thioacetamide at160oC for30h. The composition, morphologies and surfacephysicochemical properties of the as-prepared samples wereinvestigated via the characterizations, such as XRD, BET, UV-vis, XPS,FESEM, TEM, and PL. The results exhibit that SnO2/SnS2heterojunctionsemiconductor composites can be obtained via the proposed route.The photocatalytic performance for degrading RhB can be greatlyenhanced via forming the strong heterojunctions between SnO2andSnS2with narrow band gap. Under visible light irradiation, theas-obtained photocatalyst exhibited excellent photocatalyticperformance for degrading RhB with long usage life.3. One pot synthesis and photocatalytic performance of SnO2/BiOClheterojunction visible light photocatalyst.One pot synthesis route was proposed to fabricate porousflower-like spheres SnO2/BiOCl heterojunction photocatalyst by varyingreaction condition such as concentration, the reaction temperature,reaction time and other conditions. FESEM, XRD, TEM, BET and PL wereused to investigate the morphologies, crystal phases, and otherphysicochemical properties. The above results indicate that theas-prepared heterojunction photocatalysts can be utilized to degradehigh concentrated organic pollutants aqueous solution （RhB） with ahigh concentration of100mg/L under visible light irradiation owing to itsspecial porous flower-like spherical structures and the SnO2/BiOClheterojunctions. A possible mechanism of the degradation of RhB of the SnO2/BiOCl heterojunctions was proposed.