天然沸石负载La2O3-ZnO-TiO2光催化降解活性艳红K-2BP

利用80目天然斜发沸石作载体制备La2O3(0.5%)-ZnO(20%)-TiO2/沸石复合光催化剂,以20 W紫外灯为光源,在自制的光催化反应器中降解活性艳红K-2BP,考察了光照时问、空气通入量、催化剂用最、溶液初始浓度、H2O2与Fe3 投加量等对活性艳红K-2BP光催化降解率的影响.结果表明,当溶液初始浓度为60 mg/L,催化剂投加量为12 g/L,通气量为1 200 mL/min,光照2.5 h,活性艳红K-2BP的降解率可达99.2%;H2O2和Fe3投加量为4 mL/L和3 g/L时,光照1 h活性艳红K-2BP降解率分别为100%和97.2%.紫外-可见吸收光谱显示,LZTZ光催化剂町有效降解印染废水.     

La2O3/ZnO/TiO2光催化降解活性艳红K-2BP的研究

采用溶胶-凝胶法制备了La2O3/ZnO/TiO2复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La2O3/ZnO/TiO2的光催化性能.结果表明:当锌和镧的掺杂量w(zno)=20%,w(La2O3)=0.5%,煅烧温度为500℃时,La2O3/ZnO/TiO2复合光催化剂的光催化活件最高;当催化荆投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La2O3/ZnO/TiO2对活性艳红K-2BP的降解效果最好.实验证明.La2O3/ZnO/TiO2对活性艳红K-2BP的降解遵从Lang-muir-Hinshelwood动力学模型,测得其反应速率常数k=11.5 mg/(L·min);吸附常数K=2.88×10-2L/mg.     

天然沸石负载La2O3-ZnO-TiO2光催化降解活性艳红K-2BP

利用80目天然斜发沸石作载体制备La₂O₃(0.5%)-ZnO(20%)-TiO₂/沸石复合光催化剂,以20 W紫外灯为光源,在自制的光催化反应器中降解活性艳红K-2BP,考察了光照时间、空气通入量、催化剂用量、溶液初始浓度、H₂O₂与Fe³⁺投加量等对活性艳红K-2BP光催化降解率的影响。结果表明,当溶液初始浓度为60 mg/L,催化剂投加量为12 g/L,通气量为1 200 mL/min,光照2.5 h,活性艳红K-2BP的降解率可达99.2%;H₂O₂和Fe³⁺投加量为4 mL/L和3 g/L时,光照1 h活性艳红K-2BP降解率分别为100%和97.2%。紫外可见吸收光谱显示,LZTZ光催化剂可有效降解印染废水。     

RuO2/La2O3/TiO2悬浮体系中直接耐晒黑G的光催化降解

钛酸丁酯为前驱体,采用溶胶-凝胶-浸渍法制备RuO2/La2O3/TiO2复合光催化剂,以紫外灯为光源,研究了催化剂组成、煅烧温度、溶液pH值等因素对直接耐晒黑G(DFBG)光催化降解的影响.结果表明掺杂量w(La2O3)1.39%、w(RuO2)0.12%、煅烧温度500℃(2 h)、溶液pH值7.3时,光催化活性最佳.当通气量为200 mL/min,催化剂投加量为150mg时,50 mg/L的DFBG溶液经60 min降解,其降解率近100%.DFBG的光催化降解服从Langmuir-Hinshelwood动力学模型,测得相应的动力学参数k=7.42×10-3mmol/L·min,K=19.54 L/mmol.     

La2O3/ZnO/TiO2光催化降解活性艳红K-2BP的研究

采用溶胶-凝胶法制备了La₂O₃/ZnO/TiO₂复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La₂O₃/ZnO/TiO₂的光催化性能。结果表明：当锌和镧的掺杂量w(ZnO)=20%, w(La₂O₃)=0.5%, 煅烧温度为500℃时,La₂O₃/ZnO/TiO₂复合光催化剂的光催化活性最高;当催化剂投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解效果最好。实验证明,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解遵从Langmuir-Hinshelwood动力学模型,测得其反应速率常数k＝11.5 mg/(L·min);吸附常数K＝2.88×10^-2 L/mg。     

涡流空化/Fenton协同降解溶液中活性艳红K-2BP

采用涡流空化(SC)/Fenton协同降解溶液中活性艳红K-2BP,探讨了H2O2、Fe2+、pH、涡流压力以及活性艳红K-2BP初始浓度对SC/Fenton降解效果的影响。结果表明,H2O2和Fe2+的浓度过高或过低都会降低活性艳红K-2BP的降解率,低pH环境有助于活性艳红K-2BP的降解,活性艳红K-2BP的降解率随涡流压力的增大而升高,随其初始浓度的增加而降低。当活性艳红K-2BP初始质量浓度为10mg/L,H2O2质量浓度为165mg/L,Fe2+摩尔浓度为1.5×10-4mol/L,pH为4.0,涡流压力为0.8MPa时,活性艳红K-2BP降解率可达91.81%。     

壳聚糖/海藻酸钠复合絮凝剂的吸附性能

采用壳聚糖和海藻酸钠制备新型复合絮凝剂,通过正交实验考察复合絮凝剂投加量、搅拌时间、絮凝温度及pH值等因素对曙红染料废水吸附效果的影响,并采用红外光谱对产品进行表征。结果表明:最佳吸附条件为复合絮凝剂投加量0.30 g,pH值为5.00,搅拌时间为2.0 h,絮凝温度25℃时,脱色率可达97.52%。复合絮凝剂对曙红溶液的吸附等温曲线遵循Freundlich吸附等温式和Langmuir等温吸附式。     

磁性Fe_3O_4/Ag_3PO_4复合光催化剂催化降解染料废水中的孔雀石绿

利用离子交换法制备了可磁性分离并具有高效可见光催化活性的Fe3O4/Ag3PO4复合光催化剂,对制备的样品进行了粉末X射线衍射(XRD)表征。同时,用孔雀石绿溶液模拟染料废水,考察了孔雀石绿溶液的初始浓度、催化剂投加量及溶液初始pH值对复合光催化剂催化降解孔雀石绿效果的影响,并探讨了Fe3O4/Ag3PO4磁性复合光催化剂的回收及循环利用特性。结果表明,该复合光催化剂在可见光照射下表现出较高的催化活性;当孔雀石绿溶液浓度为5mg/L、复合催化剂投加量为200mg/L、溶液初始pH=3.0、可见光照20min时,Fe3O4/Ag3PO4复合光催化剂对孔雀石绿的去除率可达96%;反应结束后,磁性复合光催化剂在外加磁场作用下,易于从反应体系中分离,循环使用3次后,其光催化效率仍可达到60%。实验表明,制备的复合光催化剂对染料废水中孔雀石绿有较高的降解效率,并具有优良的回收利用性。     

溶胶-凝胶法制备复合光催化剂（MWNTs/TiO_2）工艺条件的研究

以多壁碳纳米管（MWNTs）为载体,在煅烧温度200~900℃、煅烧时间1~7 h、溶胶体系pH值为2~10的工艺条件下,采用溶胶-凝胶法制备复合光催化剂（MWNTs/TiO2）。通过其对甲基橙的光催化降解效果对比,评价各种复合光催化剂催化活性之间的差异,结果表明,随着煅烧温度的升高,复合光催化剂中纳米TiO2的晶型由锐钛型逐渐向金红石型转变,500℃时为2种晶型的混合相;pH值为2的强酸性条件有利于形成金红石晶型,pH值为5的中性及弱酸性条件则有利于形成锐钛型,而pH值为3时为2种晶型的混合相;在煅烧温度500℃、煅烧时间3 h、溶胶凝胶体系pH值为3的最佳制备工艺条件下,复合光催化剂催化活性最高,借助扫描电镜发现其TiO2均匀地包覆在多壁碳纳米管管壁上。     

类Fenton氧化-絮凝耦合处理活性艳红K-2BP的研究

以H2O2为氧化剂、聚硅硫酸亚铁(PFSSⅡ)为催化絮凝剂,两者耦合形成类Fenton试剂氧化-絮凝处理活性艳红K-2BP废水.当PFSSⅡ的铁硅摩尔比为1∶3,H2O2和PFSSⅡ的投加量分别为10 mg/L和15 mg/L(以Fe2+计)时,活性艳红的脱色率可达到98%以上,且氧化反应速率符合三级反应速率方程.与传...     

溶胶-凝胶法制备磁载光催化剂

悬浮态的光催化反应器相比固载的光催化反应器有更高的光催化效率。但是如何在光催化反应完成后使催化剂与水溶液的分离 ,成为了一个关键的问题。本研究采用溶胶 凝胶法将二氧化钛直接沉积在磁性颗粒的表面 ,制备出了磁载的光催化剂。这种催化剂在保留了磁性能具有可磁分离的基础上又具有很好的光催化降解效果。     

Inactivation of bacteria G(+)-S. aureus and G(-)-E. coli by phototoxic polythiophene incorporated in ZSM-5 zeolite

A new heterogeneous photocatalyst was prepared by oxidative polymerization of the thiophene with ferric chloride in the ZSM-5 zeolite type. The synthesized polythiophene absorbs radiation in the visible range of the electromagnetic spectrum and by illumination with visible light generates reactive oxygen species (ROS) in water medium. During illumination reactive hydroxyl radical was detected by the spin trapping EPR method. Efficiency of the photocatalyst was tested on the killing of Gram-positive bacteria Staphylococcus aureus and Gram negative bacteria Escherichia coli.     

纳米TiO_2/EP光催化降解罗丹明B废水的研究

通过溶胶-凝胶法制备出可漂浮于水面的膨胀珍珠岩（EP）负载型TiO2,研究其在水中对罗丹明B（RB）的去除效果、吸附降解动力学以及最佳工艺条件,并研究其多次回收再生后的降解效果。结果表明,浸渍3次的负载型TiO2光催化活性最高,回收5次后活性变化很小,降解率下降不到8%;光催化剂用量为0.2 g,20 mL初始浓度为10 mg/L和15mg/L RB溶液光照6 h后降解率分别达98%和74%。在实验浓度范围内,该光催化反应可用一级反应动力学方程描述。     

纳米TiO2/EP光催化降解罗丹明B废水的研究

通过溶胶-凝胶法制备出可漂浮于水面的膨胀珍珠岩(EP)负载型TiO2,研究其在水中对罗丹明B(RB)的去除效果、吸附降解动力学以及最佳工艺条件,并研究其多次回收再生后的降解效果。结果表明,浸渍3次的负载型TiO2光催化活性最高,回收5次后活性变化很小,降解率下降不到8%;光催化剂用量为0.2 g,20 mL初始浓度为10 mg/L和15mg/L RB溶液光照6 h后降解率分别达98%和74%。在实验浓度范围内,该光催化反应可用一级反应动力学方程描述。     

炉渣制光催化剂催化降解水中罗丹明B的研究

以废弃的钢铁冶炼炉渣为原料制备了光催化剂GN,并对其进行了X衍射、紫外-可见漫反射吸收光谱、比表面积及孔径分布等物性测试,通过在三相内循环流化床光催化反应器中对罗丹明B废水进行处理,确定了GN的最佳光催化氧化条件.将GN与传统的光催化剂TiO2作比较,结果表明,GN不仅具备较高的光催化活性,而且成本更低,为钢铁冶炼炉渣的循环再利用提供了一种新思路,同时也为光催化氧化技术的工业化应用提供了一条新颖、经济、可行的途径.     

Effective photodegradation of methomyl pesticide in concentrated solutions by novel enhancement of the photocatalytic activity of TiO2 using CdSO4 nanoparticles

Annihilation of electrons–holes recombination process is the main remedy to enhance the photocatalytic activity of the semiconductors photocatalysts. Doping of this class of photocatalysts by foreign nanoparticles is usually utilized to create high Schottky barrier that facilitates electron capture. In the literature, because nonpolar nanoparticles (usually pristine metals, e.g., Ag, Pt, Au, etc.) were utilized in the doping process, the corresponding improvement was relatively low. In this study, CdSO₄-doped TiO₂ nanoparticles are introduced as a powerful and reusable photocatalyst for the photocatalytic degradation of methomyl pesticide in concentrated aqueous solutions. The utilized CdSO₄ nanoparticles form polar grains in the TiO₂ matrix due to the electrons leaving characteristic of the sulfate anion. The introduced nanoparticles could successfully eliminate the harmful pesticide under the sunlight radiation within a very short time (less than 1 h), with a removal capacity reaching 1,000 mg pesticide per gram of the introduced photocatalyst. Moreover, increase in the initial concentration of the methomyl did not affect the photocatalytic performance; typically 300, 500, 1,000, and 2,000 mg/l solutions were completely treated within 30, 30, 40, and 60 min, respectively, using 100 mg catalyst. Interestingly, the photocatalytic efficiency was not affected upon multiple use of the photocatalyst. Moreover, negative activation energy was obtained which reveals super activity of the introduced photocatalyst. The distinct photocatalytic activity indicates the complete annihilation of the electrons–holes recombination process and abundant existence of electrons on the catalyst surfaces due to strong electrons capturing the operation of the utilized polar CdSO₄ nanoparticles. The introduced photocatalyst has been prepared using the sol–gel technique. Overall, the simplicity of the synthesizing procedure and the obtained featured photocatalytic activity strongly recommend the introduced nanoparticles to treat the methomyl-containing polluted water.     

Photodegradation of perfluorooctanoic acid by synthesized TiO2-MWCNT composites under 365nm UV irradiation

Degradation of perfluorooctanoic acid (PFOA) is of great importance due to its global distribution, persistence and toxicity to bioorganisms. In present study, a composite TiO₂ with multiple wall carbon nano-tubes (MWCNTs) was synthesized using sol-gel method and it was used as photocatalyst to degrade PFOA in water. The prepared composite catalyst displayed significant absorption in UV to visible light region. The loading content of TiO₂ on MWCNTs could be adjusted by changing the ratio of precursor to MWCNTs. Due to the combined effect of the adsorption ability and e⁻ transport capacity of MWCNT, the composites displayed much higher photocatalytic ability to PFOA as compared to pure TiO₂ under UV irradiation. The photocatalyst prepared with 10:1 of tetrabutyl titanate/MWCNT was the most effective. With the optimal dosage at 1.6 g L⁻¹, almost 100% of PFOA was degraded in acid medium after irradiation for 8 h. It was proposed that PFOA were mainly degraded by stepwise losing a moiety of CF₂.     

Investigation of the antibacterial effects of silver-modified TiO2 and ZnO plasmonic photocatalysts embedded in polymer thin films

Nanosilver-modified TiO₂ and ZnO photocatalysts were studied against methicillin-resistant Staphylococcus aureus on the surface and against naturally occurring airborne microorganisms. The photocatalysts/polymer nanohybrid films were prepared by spray coating technique on the surface of glass plates and on the inner surface of the reactive light source. The photoreactive surfaces were activated with visible light emitting LED light at λ?=?405 nm. The optical properties of the prepared photocatalyst/polymer nanohybrid films were characterized by diffuse reflectance measurements. The photocatalytic properties were verified with the degradation of ethanol by gas chromatography measurements. The destruction of the bacterial cell wall component was examined with transmission electron microscope. The antibacterial effect of the photocatalyst/polymer nanohybrid films was tested with different methods and with the associated standard ISO 27447:2009. With the photoreactive coatings, an extensive disinfectant film was developed and successfully prepared. The cell wall component of S. aureus was degraded after 1 h of illumination. The antibacterial effect of the nanohybrid films has been proven by measuring the decrease of the number of methicillin-resistant S. aureus on the surface and in the air as the function of illumination time. The photocatalyst/polymer nanohybrid films could inactivate 99.9 % of the investigated bacteria on different thin films after 2 h of illumination with visible light source. The reactive light source with the inner-coated photocatalyst could kill 96 % of naturally occurring airborne microorganisms after 48 h of visible light illumination in indoor air sample. The TEM results and the microbiological measurements were completed with toxicity tests carried out with Vibrio fischeri bioluminescence bacterium.     

CuO/TiO2-H2O2可见光催化亚甲基蓝脱色效果及影响因素研究

以水解法制备的锐钛矿型TiO2为载体,制备了CuO/TiO2型光催化剂.以亚甲基蓝为对象,在可见光照射下研究了H2O3加入量、pH值和催化剂投加量对脱色效果的影响,同时与改性前的TiO2催化剂进行了脱色效果的对比.结果表明亚甲基蓝在碱性条件下能较好脱色,H2O2用量和CuO/TiO2催化剂投加量分别为每1 000 mL反应液各加入10 mL和0.1 g时脱色最好;另外,TiO2催化剂也在碱性条件下能较好脱色,H2O2用量和催化剂投加量分别为每1 000 mL反应液各加入12.5 mL和0.1 g时脱色最好.最优条件下对比实验表明,CuO/TiO2型催化剂在可见光照射下具有很高的催化活性,亚甲基蓝2 h脱色率达到88%,远好于改性前的TiO2和Degussa P25催化剂.     

超声辅助La-TiO_2/膨胀珍珠岩的吸附与光催化性能

以膨胀珍珠岩（expanded perlite,EP）为载体,以钛酸正丁酯和硝酸镧为前驱体,采用浸渍法制备出掺杂镧的漂浮型La-TiO2/EP光催化剂,采用X-射线粉末衍射研究了催化剂的形态结构。以正辛烷为模拟水面烃类污染物,通过超声波辅助对此催化剂的吸附与光催化性能进行了研究。结果表明：以20～40目的膨胀珍珠岩为载体制备的5%La-TiO2/EP,经500℃焙烧2 h后对辛烷的去除效果最好。超声波可促进辛烷在催化剂表面的吸附与迁移,超声辅助下辛烷去除率可提高11.08%。