亚甲基蓝溶液的光催化降解

采用三种不同方法对TiO2粉末进行改性,制得蒙脱土/TiO2、Ag/TiO2和SO42-/TiO2催化剂。以亚甲基水蓝溶液的脱色率为指标,采用XRD、SEM和XPS等手段分析考察了3种改性催化剂的活性及抗无机离子的干扰能力。结果显示,三种改性光催化剂在溶液中的活性顺序为：蒙脱土/TiO₂>SO₄^2-/TiO₂>Ag/TiO₂>TiO₂。其中,蒙脱土/TiO2活性提高最大,在温度30 ℃和催化剂用量1.0 g·L^-1条件下,1 h内使 5.0 mg·L^-1的亚甲基蓝溶液的脱色率达90%以上,Ag/TiO₂的抗无机离子干扰能力最强。     

亚甲基蓝光度法研究基于CaO2的Fenton反应条件

CaO₂作为原位Fenton 氧化修复中H₂O₂持续供源的作用逐渐受到关注。利用亚甲基蓝分光光度法评价了基于CaO₂的Fenton反应中催化剂种类、初始pH值、CaO₂用量、催化剂和CaO₂比例、磷酸缓冲溶液浓度对羟基自由基（HO·）产率的影响。结果表明,采用Fe²⁺作为催化剂,在pH值为4、CaO₂相似文献   

新型钛基PbO2阳极电氧化降解 有机污染物的特性研究

用电沉积法制备了PbO2/SnO2+Sb2O3/Ti、Bi-PbO2/SnO2+Sb2O3/Ti、PbO2（超声）/SnO2+Sb2O3/Ti、Bi-PbO2（超声）/SnO2+Sb2O3/Ti等4种二氧化铅电极,用稳态极化曲线表征了它们的电催化性和选择性,分析了电解苯酚废水的处理效果,用加速寿命实验测定了电极寿命,用电子扫描电镜表征了沉积层晶相和形貌。结果表明：掺Bi可以提高电极的电催化性和电氧化苯酚的选择性,超声电沉积可以增大电极比表面积,提高电极的表观催化活性,显著增长电极加速寿命。     

A novel cellulose-derived carbon aerogel@Na2Ti3O7 composite for efficient photocatalytic degradation of methylene blue

A scale-up and sustainable method was developed to fabricate novel photocatalyst cellulose-derived carbon aerogel@Na₂Ti₃O₇ composite (CAT) by in situ growth of Na₂Ti₃O₇ nanowhisker on the surfaces of fibers. With a three-dimensional (3D) mesoporous network interconnected structure and a high specific surface area (248.92 m²/g), CAT exhibited excellent photocatalytic activity and methylene blue (MB) removal rate (98.3%). The photocatalytic experimental results showed that the CAT could degrade MB in the aqueous solution within 90 min. Compared with most reported catalysts, CAT exhibited a higher MB removal rate and shorter catalytic time. Therefore, the photocatalyst CAT based on environmentally friendly and low-cost cellulose displayed great application potential in the degradation of MB.     

掺锌纳米TiO_2光催化降解亚甲基蓝研究

选用掺杂锌的纳米TiO2作为光催化剂对亚甲基蓝进行降解研究。制备工艺参数对样品光催化降解亚甲基蓝的活性具有很大影响,焙烧温度为500℃,Zn2+掺入量为0.5%,催化剂的加入量为1 g/L时光催化剂对亚甲基蓝的降解效果最好;亚甲基蓝的初始浓度为5 mg/L降解速率较快。     

铂电极上氟苯电化学降解机理及动力学

引言 氟苯(FB)广泛应用于医药、农药、染料、氟碳表面活性剂以及氟塑料等行业.FB可透过皮肤进入人体,长期或短期接触会刺激眼睛、皮肤和呼吸道,破坏肝、肾及肺、中枢神经等.     

宽pH条件下Mn3O4/ACF复合阴极类电芬顿体系降解亚甲基蓝

用电化学方法将Mn₃O₄负载于活性炭纤维（activated carbon fiber,ACF）表面制备了Mn₃O₄/ACF复合阴极,与铂丝阳极构成了异相类电芬顿体系对模型污染物亚甲基蓝（MB）进行降解,考察了该体系在不同pH条件下对MB去除率,并对体系中的活性氧物种进行了检测,初步探讨了降解机理。实验结果表明,在pH 3.0、pH 5.0和pH 7.0时亚甲基蓝脱色率分别达到97.3%、99.9%、99.8%,pH5.0时TOC去除率达到88.6%,pH 7.0和pH 3.0时也分别达到了80.4%和73.4%,拓宽了电芬顿反应的适宜pH范围。体系中活性氧物种的检测结果表明,氧在阴极电还原产生H₂O₂,并与Mn₃O₄反应生成羟基自由基·OH,同时,氧的一电子还原产物超氧自由基O₂·^-也对阴极表面污染物的脱色有重要贡献。     

超声-S/TiO_2纳米颗粒可见光催化协同降解亚甲基蓝

采用共沉淀-浸渍法制备掺杂S的TiO2光催化剂,利用XRD,TEM,UV-Vis-DRs,XPS等方法对其结构、元素组成和光谱学特征进行研究,以亚甲基蓝(MB)的光催化降解反应为模型,探讨高效利用可见光降解亚甲基蓝的反应体系。实验结果表明,S掺杂最佳热处理温度为500℃。掺杂光催化剂晶型仍为锐钛矿型,其粒径变小,比表面积增大,热稳定性增加,对可见光的吸收增强。超声波对光催化降解反应有协同作用,S/TiO2在可见光下对亚甲基蓝的降解率明显高于纯TiO2。     

一种新型二氧化铅电极的研制

用二氧化铅作为电极材料，研究了用铂为基体二氧化铅电极的研制，对在不同反应条件下电镀制成的电极进行了性能测试，并用XRD，XPS，SEM等分析手段进行了表征，得到了电极制作的最佳条件，此电极具有好的应用前景。     

纳米CuO/CoFe2O4-TiO2模拟太阳光降解亚甲基蓝的性能

采用溶胶-凝胶法制备CuO/CoFe2O4粒子,并与P25复合制备纳米催化剂CuO/CoFe2O4-TiO2.通过模拟太阳光催化降解亚甲基蓝,对催化剂活性进行研究,采用SEM、TEM、XRD和UV-Vis DRS方法对催化剂进行表征.结果表明,CuO/CoFe2O4粒子均匀分散在P25微粒表面,平均粒径为60 nm.并...     

构型限制Co-P催化剂的设计合成及对亚甲基蓝的光催化降解

光催化氧化降解印染废水中的污染物具有广阔的应用前景和重大现实意义,本文对构型限制Co-P化合物进行了设计合成,采用常规溶液反应法制备Co-P化合物光催化剂,并以亚甲基蓝模拟高浓度印染废水中的污染物,通过考察催化剂对亚甲基蓝的降解来评估催化剂的活性。考察了金属配比、催化剂用量、催化时间、催化温度对催化效果的影响。采用X射线衍射、红外光谱和扫描电镜等手段对催化剂进行了分析表征,结果表明：Co²⁺与有机膦成功配位,所制得的沉淀中主要含Co-P化合物,还含有少量的有机膦和其他杂质,Co-P化合物晶体间有许多孔状结构,对亚甲基蓝具有良好的吸附和光降解效果;最佳催化剂制备原料比例为：1.4-（双二苯基膦）丁烷∶六水合氯化钴为2∶1;最佳催化条件为最佳催化剂用量50mg,最佳光照时间3h,最佳催化温度50℃,在本次研究的最佳条件下污染物降解率可达15.45%,即4.6mg/L,以Ⅲ级废水中染料浓度约为5mg/L计算,其降解率达92%以上,可望在印染废水污染物降解中得到广泛应用。     

玻璃镀膜二氧化钛制备及降解亚甲基蓝研究

用溶胶-凝胶法在普通玻璃基体上制备了多层纳米二氧化钛薄膜,并用它来光催化降解有机染料亚甲基蓝。研究了镀膜层数、焙烧温度、通入空气和底物浓度对光催化降解率的影响。发现最佳镀膜层数为5层,最佳焙烧温度为550℃时,经TEM透射电镜观察,发现此温度焙烧的二氧化钛是处于催化效率最高的锐钛矿和金红石矿的混合相,降解10 mL浓度为5 mg/L的亚甲基蓝1 h的脱色率达78%。重复使用3次后脱色率基本不变,延长光催化时间,脱色率可以提高。     

ZnO-TiO2纳米纤维的制备及亚甲基蓝的太阳光催化降解

以钛酸四丁酯〔Ti(OC4H9)4〕、硝酸锌和聚乙烯吡咯烷酮(PVP)为原料,采用溶胶-凝胶法和静电纺丝法制备无机有机复合的PVP/ZnO-TiO2纤维,高温焙烧制得直径100～200 nm的ZnO-TiO2纳米纤维。通过差动-热重(DSC-TGA)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)等进行了表征,并测定了其对亚甲基蓝溶液的太阳光催化性能。结果表明,w(ZnO)=3%时,ZnO-TiO2纳米纤维对亚甲基蓝催化活性最高,太阳光照射6 h后降解率达99.4%,重复使用8次降解率仍然在95%以上。     

Self-standing Janus nanofiber heterostructure photocatalyst with hydrogen production and degradation of methylene blue

A highly efficient, stable, easily recyclable carbon-based [g-C₃N₄/C]//[TiO₂/C] Janus nanofibers heterostructure photocatalyst (gT-JNHP) was first designed and constructed through the combination of conjugative electro-spinning with subsequent calcination procedure. gT-JNHP with novel Janus structure consists of two sides: one side is g-C₃N₄/C nanofiber that absorbs visible light (VL), and the other side is TiO₂/C nanofiber that can capture ultraviolet light (UL), and the two strands of nanofibers are tightly combined together to form the unique heterostructure Janus nanofiber, which can make full use of sunlight (SL). gT-JNHP presents better remarkably boosted photocatalytic performance in comparison with the counterpart g-C₃N₄/C, TiO₂/C, or their mechanical mixture, and the degradation efficiencies of methylene blue in gT-JNHP-2, respectively, are 95.1% (160 min) and 98.6% (140 min), as well as hydrogen evolution rates reach up to 12.40 and 16.72 mmol h^–1 g^–1 under VL and simulated SL, respectively, thereby displaying the excellent dual functions of high-efficient hydrogen release and removal of organic contaminant. The outstanding photocatalytic property is ascribed to the joint effect among the unique Janus-typed heterostructure, catalyst components, and electrically conductive carbon fiber, achieving close contact between the interfaces, effective separation of photo-excited carriers, strong light capture ability, and many more exposed active sites, etc. Feasible photocatalytic mechanisms are advanced. Moreover, gT-JNHP owns the characteristics of flexible self-standing, easy recycling, and superb durability. The constructing mechanisms of Janus nanofibers and gT-JNHP are discussed in detail, and the novel fabricating techniques are established. The designing idea and construction techniques adopted in this paper are popularized for research and development of other peculiar uni-dimensional dual-functional nanofibrous photocatalysts.     

中空多孔磁性Fe3O4/纤维素/海泡石微球异相Fenton催化降解亚甲基蓝

为开发一种高效可循环利用的磁性生物质基催化剂，以微晶纤维素和纳米Fe3O4为原料，采用包埋法制得Fe3O4/纤维素（Fe3O4/MCC）溶液，将海泡石（SEP）掺入至Fe3O4/MCC中，制得磁性纤维素/海泡石复合微球（Fe3O4/MCC/SEP）。通过SEM、FTIR、VSM等对磁性微球的形貌、化学结构及磁性能进行了表征，探讨了微球作为芬顿催化剂对亚甲基蓝（MB）染料的降解效果及机理。结果表明，Fe3O4/MCC/SEP微球呈现出优异的中空多孔结构和超顺磁性。当MB浓度为10 mg/L、pH为3、Fe3O4/MCC/SEP的投入量为0.02 g，H2O2用量为5 mL时，反应240 min对MB的Fenton催化降解率高达99%。此外，经过5次循环利用后，对MB的降解率仍达83%。     

杂多酸/Fe3O4磁性催化剂的制备及其对次甲基蓝溶液的降解

采用浸渍法将磷钨酸、磷钼酸和硅钨酸等杂多酸负载在Fe3O4磁性材料上,并将杂多酸/Fe3O4磁性材料作为光催化剂用于降解次甲基蓝溶液,考察了光源类型（紫外光与太阳光）、杂多酸种类及催化剂用量等对光催化降解效果的影响。结果表明,在250 W汞灯照射、次甲基蓝溶液浓度20 mg·L-1、降解体系pH=5.5、光催化剂用量30 mg和光催化120 min条件下,次甲基蓝降解率达85%,负载型杂多酸/Fe3O4磁性催化剂对次甲基蓝的降解效果明显优于相应单一的Fe3O4或杂多酸催化剂。     

Fe/TiO_2-Al_2O_3催化H_2O_2降解亚甲基蓝废水的研究

采用浸渍-焙烧法制备了Fe/Ti O2-Al2O3、Fe/Ce O2-Al2O3复合催化剂,以H2O2作为氧化剂,对亚甲基蓝废水进行降解处理,考察了催化剂加入量、H2O2加入量、p H、温度以及初始浓度的变化等因素对处理效果的影响。结果表明:Fe/Ti O2-Al2O3的催化性能稍优于Fe/Ce O2-Al2O3,并且在p H=5,温度为65℃条件下,当催化剂加入量为0.15 g、H2O2加入量为15 m L、反应时间为60 min时降解率即可达到97%以上。     

Anodic oxidation of the dye materials methylene blue,acid blue 25, reactive blue 2 and reactive blue 15 and the characterisation of novel intermediate compounds in the anodic oxidation of methylene blue

Anodic oxidation of the dye molecules, methylene blue, acid blue 25, reactive blue 2 and reactive blue 15 in chloride solution leads to colour destruction but UV and TOC data show that the oxidation reactions do not lead to complete destruction of the organic molecules. Analysis of the anodic oxidation products of [3,7‐bis (dimethylamino) phenothiazinium] chloride (methylene blue) in a chloride solution provides evidence for formation of seven neutral and two charged intermediates. The main intermediate is identified by its X‐ray diffraction crystal structure and accurate mass spectrometry as the novel leuco dye 4,6‐dichloro‐7‐dimethylamino‐3H‐phenothiazin‐3‐one, C₁₄H₁₀Cl₂N₂OS (I) formed by replacement of one of the dimethylamino groups of methylene blue with oxygen accompanied by regiospecific chlorination of the carbocyclic systems. The mass spectra of other intermediates formed are interpreted in terms of the structure of I. © 2002 Society of Chemical Industry     

TiO<Subscript>2</Subscript>-mediated photoelectrochemical decoloration of methylene blue in the presence of peroxodisulfate

Nanosized TiO₂ films on stainless steel were prepared by electrophoretic deposition and characterized by X-ray diffraction analysis and photo-voltammetry. The decoloration of methylene blue (MB) dye was used as a test reaction for the evaluation of photoelectrocatalytic activity of the prepared TiO₂ coatings. The influence of applied potential and potassium peroxodisulfate on the rate of MB decoloration was investigated. The possible mechanisms of MB oxidation under various experimental conditions are discussed.