Preparation Of Composite Nano-sized SnO₂ Based Photocatalyst And Its Degradation Of Marine Diesel Oil Pollution

With the increasing attention of human beings to marine resources,more and more means of development have been popularized,and the accompanying marine oil pollution is inevitable.Tin dioxide is a wide band gap N-type semiconductor metal oxide with unique optical,electrical and catalytic properties.It has become a widely used photocatalytic material.In this paper,the photocatalytic degradation of diesel oil pollution in seawater with nanometer SnO₂ as the substrate has achieved remarkable resultsThe effects of catalyst dosage,catalyst concentration,initial oil concentration,pH of treated oil seawater,hydrogen peroxide concentration,and light reaction time on the effect of photocatalytic degradation of diesel oil were investigated.Nano-SnO₂ was prepared by chemical co-precipitation method,and the composite nanometer SnO₂ based rigid catalyst was prepared by doping modification,which improved the photocatalytic performance.The photocatalytic kinetics of doped modified ZnO/SnO₂ photocatalyst was studied.Nano-sized SnO₂ photocatalyst,nanometer Cu/SnO₂ photocatalyst and nano photocatalyst were prepared by coupling agent method.The photocatalytic degradation of diesel oil in seawater by self-made supported photocatalyst was studied.The conclusions obtained in this paper are as follows:?1?Semiconductor SnO₂ nano-photocatalyst was prepared by chemical precipitation method under laboratory conditions.The structure and grain size of the catalyst were characterized by SEM and XRD tests.The factors influencing the photocatalytic degradation of diesel oil pollutants in seawater by nanometer SnO₂ photocatalyst were studied by changing the experimental conditions.The experimental conditions of photocatalytic degradation of diesel oil pollutants in seawater with nanometer SnO₂photocatalyst were optimized by orthogonal test.The results showed that the prepared samples were rutile SnO₂ particles.The average diameter is 40.3 nanometers.Oil pollution concentration is 0.15g/L,the amount of SnO₂ calcined at 400?is 0.2g/L,The orthogonal experiment shows that the pH is 8,hydrogen peroxide is 0.2g/L,the reaction time is 2h,and the removal rate of oil pollution in seawater is 89.24%.?2?Characterization of self-made photocatalysts by XRD,SEM and other test methods showed that the prepared sample was rutile SnO₂ particles with an average size of 25.60??.Self-made composite Cu/SnO₂ nanophotocatalysts have better stability than pure SnO₂ nanophotocatalysts.The efficiency of degradation of marine diesel oil pollution by Cu/SnO₂ composite nanometer photocatalyst under ultraviolet light was studied by changing the experimental conditions.The concentration of 0.15g/L,the dosage of composite nano-tin dioxide photocatalyst with doping ratio of 0.03 at 400?is0.3g/L,The orthogonal experiment showed that when UV irradiation pH was 9,hydrogen peroxide addition amount was 0.3g/L,the reaction time is 3 h,the removal rate of oil pollution in seawater is 89.41%.?3?NanocrystallineZnO/SnO₂ photocatalysts were prepared by chemical coprecipitation method and characterized by XRD.The results showed that the prepared catalysts were still tetragonal rutile with good crystallization.The efficiency of degradation of marine diesel oil pollution by ZnO/SnO₂ composite nanometer photocatalyst under ultraviolet light was studied by changing the experimental conditions.oil pollution concentration was 0.3g/L under ultraviolet light irradiation.0.05g/L,of which the dosage of composite nano-tin dioxide photocatalyst is 0.4g/L,The orthogonal experiment showed that when pH was 8,hydrogen peroxide addition was 0.3g/L,the reaction time is 2h,the removal rate of oil pollution in seawater is 91.50g/L,the calcined doping ratio is 0.25 at 400?.?4?The experiments of nanometer ZnO/SnO₂ photocatalyst degradation of the water pollution of reaction kinetics was studied,in Langmuire-Hinshelwood?L-H?,on the basis of dynamic model,investigates the catalyst preparation conditions of ZnO doping amount,initial concentration,the oil nanometer ZnO/SnO₂ photocatalyst catalyst dosing quantity and the influence of four factors H₂O₂ concentration,results showed that the photocatalytic oxidation reaction pseudo-first-order reaction kinetics equation.?5?The ZnO/SnO₂ and Cu/SnO₂ composite photocatalyst supported on multiplanar spheres of polypropylene has the characteristics of large specific surface area,good stability,cheap and easy to obtain,uniform film formation and long-term stable preservation without easy shedding.The results of treatment of diesel oil pollution in seawater by two kinds of supported composite photocatalysts show that the amount of polypropylene ball with good loading is the same?the dosage is 0.5g/L?and the initial oil pollution is the same when the doping ratio of catalyst is 0.25 and the amount of polypropylene ball with good loading is the same.When the concentration is 0.3g/L,the reaction time is 2h,the removal rate is 95.75%,when the catalyst doping ratio is 0.03,the number of loaded polypropylene balls is the same?the dosage is 0.5g/L?,the initial concentration of oil pollution is 0.5g/L,the reaction time is 3h,the removal rate is95.92%.The doping ratio of Cu/SnO₂ photocatalyst to diesel oil is 0.25.The supported ZnO/SnO₂ photocatalyst is suitable for rapid treatment of low concentration diesel oil pollution.The supported Cu/SnO₂ photocatalyst with doping ratio of 0.03 is suitable to deal with the diesel oil pollution of 0.3g/L photocatalyst quickly.The polypropylene ball of the supported ZnO/SnO₂ composite photocatalyst is cyclically used to verify its loading effect.The removal rates were 95.50%,93.52%and86.21%.