新型杂多酸盐光催化降解亚甲基蓝染料废水

以水热自组装法合成的新型杂多酸盐[PMo₈V₆O₄₂][Co(Phen)₂][Him]₂·2H₃O·3H₂O(1),通过红外光谱、拉曼光谱、紫外-可见光谱、光电子能谱和X粉末衍射等技术手段进行表征。 以此物质为催化剂光催化降解亚甲基蓝染料废水。 分别讨论催化剂投加量、亚甲基蓝废水初始浓度、废水溶液酸度(pH)对亚甲基蓝降解率的影响。 实验结果表明:催化剂投加量为50 mg/L、亚甲基蓝初始浓度为4 mg/L、模拟废水溶液的初始pH=1、降解时间220 min时,废水降解率可达到99.2%。 光催化动力学分析显示,以合成杂多酸盐为催化剂光催化降解亚甲基蓝废水降解过程满足一级动力学方程,该一级方程反应速率常数为0.0144 min^-1,拟合常数为0.9918。 另外,此催化剂还表现出较好的重复使用性能,连续使用5 次后降解率仍为92.4%。     

TiO_2-SBA-15催化剂的制备、表征及光催化降解甲基橙

以钛酸四丁酯为钛源,以介孔分子筛SBA-15为载体,采用简单的方法制备TiO2-SBA-15催化剂,并采用FT-IR,XRD和N2吸附-脱附等方法对其进行表征.另外,将制备的TiO2-SBA-15催化剂应用于光催化降解甲基橙溶液,并讨论了钛含量、甲基橙浓度及溶液pH值对降解率的影响.结果表明:在钛酸四丁酯起始加入量为3.2mL,甲基橙浓度为10mg/L,溶液pH=3的条件下,TiO2-SBA-15光催化降解甲基橙的降解率可达到100%.     

NiFe2O4对刚果红的光催化降解性能研究

采用水热法合成了尖晶石型NiFe₂O₄,并利用X射线粉末衍射仪对其物相进行了表征,利用紫外-可见分光光度计对其光催化降解刚果红的性能进行了研究。以刚果红为光催化降解底物,探究了刚果红初始浓度、催化剂用量、溶液pH、不同光源等因素对NiFe₂O₄光催化降解刚果红活性的影响。结果表明,当刚果红溶液浓度为20 mg/L、催化剂NiFe₂O₄的用量为0.065 g、pH 2~10、在太阳光下照射480 min时,刚果红的降解率高达99%以上,催化剂性能稳定,适合处理刚果红类有机污染物。     

超声波-二氧化钛光催化耦合法降解高效氯氰菊酯

采用超声波-TiO2光催化耦合法降解高效氯氰菊酯,考察了高效氯氰菊酯初始浓度、降解时间、溶液pH、催化剂用量等对高效氯氰菊酯农药残留的降解效果,并利用水果进行了实物模拟.结果表明:利用超声波-TiO2光催化耦合法能够有效地降解高效氯氰菊酯农药残留.在弱酸环境中,当纳米TiO2投放量为1.2g/L时,经2h超声催化降解,不同浓度的高效氯氰菊酯农药稀释液均被有效降解,降解率最高可达98.3%.     

双配体仿酶催化剂的制备及其光催化降解水中对苯二酚

以天然氯化血红素和咪唑为原料,制备了咪唑轴向五配位型的双配体配合物,并将其负载于羟基功能化的纤维素磁微球表面。 通过紫外-可见分光光度、傅里叶变换红外光谱、透射电子显微镜、热重分析和振动样品磁强（VSM）对催化剂进行表征。 在模拟太阳光照射下,以水中溶解氧为氧化剂,考察了该催化剂降解模拟废水中有机污染物对苯二酚（HQ）的性能。 结果表明,在300 W氙灯照射下,当催化剂用量0.2 g/L、HQ初始浓度20 mg/L及pH值为6的条件下,6 h后HQ的降解率达到96.97%,催化剂重复使用5次后,降解率仍可达92%以上。同时对该催化剂光催化降解对苯二酚的机理进行了初步研究。     

活性炭负载纳米TiO2光催化降解性能研究

本文研究活性炭负载纳米TiO2的光催化降解性能和影响甲基橙废水处理的主要因素。结果表明:用溶胶-凝胶法制备的TiO2-活性炭催化剂具有比表面积大、分散性高、光催化降解性能好、可重复利用等优点;采用30W高硼紫外光灯,TiO2-活性炭光催化降解浓度为1500mg/L甲基橙废水的最优工艺条件是:催化剂活化温度为700℃、用量为1.0g/L、废水起始pH值为1、反应温度为45℃、光照时间为50m in。在此条件下,甲基橙和CODC r的去除率分别达99.8%和99.7%。     

铁锌柱撑膨润土催化剂的制备及其对甲基橙废水的光催化降解性能

采用微波辐照促进的溶胶浸渍法制备了铁锌柱撑膨润土催化剂;用制备的催化剂对甲基橙溶液在可见光照射下进行降解,探讨了铁负载量、H2O2质量浓度、溶液初始pH、反应时间和催化剂投加量对甲基橙降解率的影响,并考察了催化剂的重复利用性能.结果表明,在pH为3、H2O2质量浓度100mg/L、催化剂投加量1.5g/L、反应时间为2h条件下,甲基橙降解率可达97%.     

Fe-Ni 共掺杂 ZnO 的制备及其光催化降解甲基橙活性

 采用溶液法制备了 Fe-Ni 共掺杂 ZnO 光催化剂, 并运用 X 射线衍射、扫描电镜和原子发射光谱等对催化剂进行了表征. 以甲基橙 (MO) 为模型污染物, 评价了样品的光催化活性, 考察了甲基橙初始浓度及其 pH 值, 以及催化剂用量等对光催化反应性能的影响. 结果表明, Fe-Ni 共掺杂降低了 ZnO 的结晶度, 并促进了晶粒的长大. 光催化降解反应表明, Fe-Ni 共掺杂显著提高了 ZnO 光催化降解甲基橙的活性, 当催化剂用量为 0.6 g/L, 经 120 min 紫外光照射时, 可使甲基橙溶液 (10 mg/L) 降解率达到 93.5%. 关键词：铁; 镍; 共掺杂; 氧化锌; 光催化; 甲基橙; 降解     

SnO_2@PW_(12)的制备及对废水中亚甲基蓝的降解

采用简单浸渍法制备了SnO2@PW12催化材料,通过XRD和TEM对其结构进行了表征,研究了该催化材料对有机染料亚甲基蓝降解的催化活性。讨论了催化剂投加量、亚甲基蓝溶液的初始浓度、酸度等对催化降解效果的影响。结果表明,当溶液酸度为pH=4,催化剂用量为50mg/L,浓度为5mg/L亚甲基蓝溶液在30W的紫外灯下照射40min脱色率可达89.72%。SnO2@PW12光催化降解亚甲基蓝为一级动力学反应。     

TiO2光催化降解苯和甲苯的动力学研究

利用溶胶-凝胶法制备了粒径约为13nm、晶型为锐钛矿相和金红石相混晶的TiO2光催化剂,并利用此催化剂对挥发性有机污染物苯和甲苯进行了光催化降解研究,对不同的催化剂用量、光源、污染物的初始浓度以及氧气对光催化反应速率的影响进行了研究。结果表明,光催化降解甲苯和苯的反应均符合假一级动力学方程,光强与光催化降解甲苯的反应的速率常数之间呈指数关系,光波长对光催化降解苯的影响也很显著;随着甲苯和苯初始浓度的增加,光催化反应速率常数降低;氧气加快了光催化降解甲苯和苯的速率;对于光催化降解初始浓度为37.6μmol/L的甲苯而言,催化剂的最佳使用量为0.30g,对于光催化降解初始浓度为9.0μmol/L的苯来说,催化剂的最佳用量为0.10g。     

以工业粉煤灰为原料制备 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂及其催化性能

2-仲丁基-4,6-二硝基苯酚(DNBP)作为杀虫剂、除草剂和烯烃基芳香族化合物阻聚剂而被广泛地应用于工农业生产中.在 DNBP生产和使用过程中,会产生大量难以降解的有机废水,从而对人类和生态环境造成极大危害.因此,开展含 DNBP废水的处理技术和方法研究具有重要的现实意义. TiO2半导体材料由于具有良好的光化学特性和电化学行为,近几十年来一直是光催化领域的研究热点.在能量等于或大于 TiO2的带隙能级的辐照光照射下, TiO2可以产生光生电子/空穴对(e-/h+).光生电子和空穴分别与 TiO2表面被吸附的 H2O和 O2分子反应,生成具有强氧化性的活性羟基自由基(?OH),对硝基酚类有机污染物具有较强的降解能力. TiO2光催化反应属于非均相反应,反应在催化剂的表面进行,催化剂对污染物的吸附是影响其催化降解性能的重要因素.但是,传统 TiO2光催化剂存在比表面积小,对有机污染物吸附能力差,光生电子与空穴易于复合等缺陷,限制了 TiO2光催化技术的进一步发展和在水处理领域中的大规模应用.我们基于气凝胶具有多孔性、大比表面积和高孔隙率的特点,以富含硅、铝的工业废弃物粉煤灰为反应原料,首先利用碱熔法和常压干燥技术制备出 SiO2-Al2O3气凝胶.在此基础上,以钛酸四丁酯(TBOT)为反应前体, SiO2-Al2O3气凝胶为载体,利用酸催化溶胶-凝胶法(sol-gel)制备出 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂.利用 X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)、N2吸附-脱附(BET)、紫外-可见吸收光谱(UV-vis)等分析测试技术对所制备的 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂结构进行了表征.结果显示,在 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂中,粒径尺寸为10~30 nm的锐钛矿型 TiO2纳米颗粒均匀分散在 SiO2-Al2O3气凝胶载体上. TiO2/SiO2-Al2O3气凝胶三元复合光催化剂呈现典型介孔材料的 IV型等温线. SiO2-Al2O3气凝胶的加入极大提高了 TiO2光催化剂的比表面积和对有机污染物的吸附性能,但是对 TiO2光波吸收范围影响不大.在制备出 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂基础上,进一步对其在可见光条件下的光催化性能进行了研究.以500 W的 Xe灯光源模拟自然太阳光, DNBP为探针污染物分子,系统考察了可见光照射条件下溶液 pH值、光催化剂用量、光反应时间、DNBP溶液初始浓度不同因素对 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂催化活性的影响.结果表明, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP有机污染物的吸附率和光降解率明显高于纯 TiO2样品.在 DNBP溶液初始浓度为0.167 mmol/L, pH =4.86,催化剂用量6 g/L,光照时间5 h的条件下, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP的降解率几乎高达100%.根据 Langmuir-Hinshelwood方程,在低浓度下光催化降解反应符合一级反应动力学.所制备的 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂具有良好的稳定性和重复利用性能.重复利用5次后, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP的降解率仍高达90%以上.利用紫外-可见分光光度计、气相-质谱联用仪对 DNBP降解中间产物进行了分析,探讨了 DNBP的光催化降解机理.     

Photocatalytic ozonation degradation of ciprofloxacin using ZnO nanoparticles immobilized on the surface of stones

Ciprofloxacin is used in the treatment of bacterial infections. Because ciprofloxacin is not effectively degraded by biological processes, advanced oxidation processes such as photocatalytic ozonation are applied to remove this antibiotic from wastewater. The aim of this study was to investigate photocatalytic ozonation for the removal of ciprofloxacin from aquatic environments and optimization of the effective parameters of the process. For this purpose, ZnO nanoparticles were synthesized using the thermal method and immobilized on the surface of stones. The structural properties of the nanoparticles were determined by XRD, TEM, Photoluminescence (PL) and SEM. Experiments were carried out in a Plexiglas reactor supported with the continuous injection of ozone. The effective parameters for removal efficiency were reaction time, initial concentration of ciprofloxacin, pH, photocatalyst concentration and reaction kinetics. The highest ciprofloxacin removal efficiency occurred at the following optimal conditions: pH of 7, reaction time of 30?min, photocatalyst concentration of 3?g/L and initial ciprofloxacin concentration of 10?mg/L. Removal efficiency of 96% was obtained under these conditions. Linear kinetic models showed that the process followed pseudo-first order and Langmuir-Hinshelwood kinetics. This process had a high removal efficiency and suitable for removal of ciprofloxacin from aquatic environments.GRAPHICAL ABSTRACT     

Enhanced photocatalytic performance of magnetite/TS-1 thin film for phenol degradation

Photocatalytic degradation method is an emerging technique for complete removal of pollutants. Several semiconductor photocatalysts are reported as photocatalysts for industrial wastewater treatment in environmental applications. In this study Magnetite/TS-1 composite materials was used for photocatalytic degradation of phenol. Magnetite nanoparticles (MNP) (10 wt%) were dispersed with nanocrystalline Titanium Silicate-1 zeolite (TS-1). The Magnetite/TS-1 composite materials were characterized with various techniques. The structural analysis reveals the presence of MNP and zeolite-MFI phases in Magnetite/TS-1 composite materials. The average particles size of the magnetite nanoparticles is less than 5 nm and that of the composite nanoparticles are in the range of about 90 nm with micropore volume 0.110 cm³/g and the external surface area 120 m²/g. The photocatalytic experiments were carried out in a thin film flow photoreactor under UV radiation. The results showed that Magnetite/TS-1 composite materials exhibited improved activity for the degradation of phenol compared to TS-1. Preliminary studies proves that aeration is necessary for the photocatalytic reaction. The reaction parameters such as flow rate, pH and phenol concentration are optimized as 8 ml/min, pH 7.0 and 75 mg/L respectively. To understand the active species involved in the degradation of phenol radical scavengers such as NaI, benzoquinone and isopropyl alcohol are used to trap hole (h⁺), superoxide anion radical and hydroxyl radical (OH), respectively. From the obtained results it is envisaged that hydroxyl radicals are predominantly involved in complete oxidation of phenol. The extent of degradation of phenol was determined by measuring the amount of CO₂ formed in the reaction. The results confirms that 99.6 % carbon in phenol is converted to CO₂.     

C/Fe-Bi_2WO_6光催化氧化诺氟沙星废水的效能及其机理

采用树脂碳化和水热两步法制备C/Fe-Bi_2WO_6光催化剂,对不同光催化剂光催化降解诺氟沙星溶液的去除效果进行对比研究。考察了条件因素对诺氟沙星(NOR)溶液在模拟太阳光下光催化氧化降解的影响规律。结果表明,在实验条件下,NOR光催化氧化降解符合L-H拟一级反应动力学模型,在NOR溶液初始浓度10 mg/L、溶液p H=7.0、催化剂用量0.75 g/L、H_2O_2浓度为200 mg/L、500 W氙灯照射60 min条件下,NOR完全分解,表观速率常数K_(app)为0.0751 min-1。采用分子荧光光谱法,对C/Fe-Bi_2WO_6光催化氧化去除NOR体系中羟基自由基生成规律进行研究,并推测了反应机理。结合LC-MS的分析结果,推测了NOR可能的降解路径和中间产物。     

对甲基苯磺酸废水光催化氧化处理的正交试验研究(英文)

在TiO2悬浮体系下,采用对甲基苯磺酸模拟废水进行半导体光催化氧化降解静态试验;利用正交试验研究了光催化氧化降解的主要影响因素(pH值、催化剂用量、光照强度、光照时间).结果表明:在一定条件下,催化剂投加量、溶液pH、照射光强度及光照时间均存在一个最佳值;依据其影响对甲基苯磺酸废水光催化降解反应的大小,各因素排列顺序为:光照时间(光照强度(初始pH(催化剂用量.在试验最佳条件下(pH=3,催化剂用量80 mg.L-1,光照强度500 W,光照时间120 min),对甲基苯磺酸能够完全降解.     

Photocatalytic degradation and adsorption of 2-naphthol on suspended TiO2 surface in a dynamic reactor

The photocatalytic oxidation of 2-naphthol has been investigated at room temperature in a dynamic photoreactor with system UV/O2 (air) and aqueous suspension of titanium dioxide TiO2 irradiated under a variety of conditions. The kinetics of disappearance of pollutant were affected by several operating parameters such as TiO2 mass, concentration of the substrate and reaction pH. The experiments were measured by high performance liquid chromatography. A Langmuir-Hinshelwood model was found to be accurate for photocatalytic degradation and indicates that adsorption of the solute on the surface of semiconductor particles plays a role in photocatalytic reaction.     

Adsorption Reaction Dynamics of Systems Lysozyme and Nanodiamond/Nanosilica at pH=7-13

Adsorption reactions between surfaces of nanodiamond and nanosilica with diameter of 100 nm prepared as suspension solutions of 0.25 μg/μL and lysozyme molecule with different concentrations of 7 mmol/L PPBS at pH=7, 9, 11, and 13 have been investigated by fluores-cence spectroscopy. Adsorption reaction constants and coverages of lysozyme with different concentrations of 0-1000 nmol/L under the influences of different pH values have been ob-tained. Helicities and conformations of the adsorbed lysozyme molecules, free spaces of every adsorbed lysozyme molecule on the surfaces of nanoparticles at different concentrations and pH values have been deduced and discussed. The highest adsorption capabilities for both sys-tems and conformational efficiency of the adsorbed lysozyme molecule at pH=13 have been obtained. Lysozyme molecules can be prepared, adsorbed and carried with optimal activity and helicity, with 2 and 10 mg/m2 on unit nanosurface, 130 and 150 mg/g with respect to the weight of nanoparticle, within the linear regions of the coverages at around 150-250 nmol/L and four pH values for nanodiamond and nanosilica, respectively. They can be prepared inthe tightest packed form, with 20 and 55 mg/m2, 810-1680 and 580-1100 mg/g at threshold concentrations and four pH values for nanodiamond and nanosilica, respectively.     

Photocatalytic OH radical formation and quantification over TiO2 P25: Producing a robust and optimised screening method

Photocatalytic oxidation of coumarin to 7-hydroxycoumarin was used in order to identify the optimum conditions and the potential limitations of a photocatalytic screening method.     

粒径可控的纳米铁酸铋的制备及其光催化性能

采用改进的聚丙烯酰胺凝胶法制备了BiFeO3纳米颗粒,利用热重-差热、红外光谱及X射线衍射等手段研究了干凝胶的热分解及BiFeO3的成相过程.结果表明,在600℃煅烧可制备出高纯的BiFeO3纳米颗粒.同时发现,随着双丙烯酰胺含量的增加,所得样品晶粒尺寸逐渐减小,从而制备出平均粒径约52～110nm的系列BiFeO3颗...     

Photochemical degradation of an anionic surfactant by TiO<Subscript>2</Subscript> nanoparticle doped with C,N in aqueous solution

Novel C,N-doped TiO₂ nanoparticles were prepared by a solid phase reaction. The catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results showed that crystallite size of synthesized C,N-doped TiO₂ particles were in nanoscale. UV light photocatalytic studies were carried out using sodium naphthalenesulfonate formaldehyde condensate (SNF) as a model pollutant. The effects of initial concentration of surfactant, catalyst amount, pH, addition of oxidant on the reaction rate were ascertained and optimum conditions for maximum degradation was determined. The results indicated that for a solution of 20 mg/L of SNF, almost 98.7% of the substance were removed at pH ~ 4.0 and 0.44 g/L photocatalyst load, with addition of 1 mM K₂S₂O₈ and irradiation time of 90 min. The kinetics of the process was studied, and the photodegradation rate of SNF was found to obey pseudo-first-order kinetics equation represented by the Langmuir–Hinshelwood model.