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Xueyan Li Lei Shi Desong Wang Qingzhi Luo Jing An 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(8):1187-1193
BACKGROUND: Semiconductor TiO2 has been investigated extensively due to its chemical stability, nontoxicity and inexpensiveness. However, the wide band gap of anatase TiO2 (about 3.2 eV) only allows it to absorb UV light. TiO2 nanoparticles modified by conditional conjugated polymers show excellent photocatalytic activity under visible light. However, these conjugated polymers are not only expensive, but also difficult to process. Polyvinyl chloride (PVC) was heat‐treated at high temperature to remove HCl and a C?C conjugated chain structure was obtained. When TiO2 nanoparticles were dispersed into the conjugated polymer film derived from PVC, this composites film exhibited high visible light photocatalytic activity. RESULTS: The photocatalytic activity of TiO2/heat‐treated PVC (HTPVC) film was investigated by degrading Rhodamine B (RhB) under visible light irradiation. The photodegradation of RhB follows apparent first‐order kinetics. The rate constants of RhB photodegradation in the presence of the TiO2/HTPVC films with different mass content of TiO2 are 16–56 and 4–14 times that obtained in the presence of the pure HTPVC and TiO2/polymethyl methacrylate (PMMA) composite film, respectively. The TiO2/HTPVC film showed excellent photocatalytic activity and stability after 10 cycles under visible light irradiation. CONCLUSION: TiO2/HTPVC film exhibits high visible light photocatalytic activity and stability. Copyright © 2012 Society of Chemical Industry 相似文献
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Jordi Palau Josep M. Penya‐Roja Carmen Gabaldón Francisco Javier Álvarez‐Hornos Feliu Sempere Vicente Martínez‐Soria 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(2):273-281
BACKGROUND: One of the most important industrial sources of volatile organic compounds (VOCs) is related to coating and painting applications. In this sense, photocatalytic oxidation can become an innovative and promising alternative for the remediation of air polluted by VOCs. In this study the UV photodegradation of m‐xylene, toluene and n‐butyl acetate, as representative compounds of paint solvents, was carried out in an annular reactor using a TiO2–glass wool supported catalyst. RESULTS The removal of each component and their mixture, simulating an industrial emission, was evaluated under different operational conditions. A maximum elimination capacity of 12, 18 and 80 mg C m?3 s?1 was reached for m‐xylene, toluene and n‐butyl acetate, respectively. A simple Langmuir–Hinshelwood kinetic model was used to match the experimental data. Photocatalytic oxidation was found to be more effective for all compounds when humidified air was used. CONCLUSIONS: No mass transfer limitation was found under the experimental conditions. n‐butyl acetate was the easiest to degrade and m‐xylene the most recalcitrant. In the abatement of the mixture, competitive adsorption between the pollutants was observed, with the degradation of toluene especially hindered. A nearly linear correlation was found between the UV light intensity and kinetic constants. Copyright © 2010 Society of Chemical Industry 相似文献
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纳米管TiO2光催化降解丙烯的研究 总被引:5,自引:1,他引:4
制备了纳米管TiO2并研究了不同pH和不同处理温度对纳米管TiO2光催化氧化丙烯的影响,采用能量色散分析、荧光光谱和X射线衍射谱等方法对影响因素进行了初步探讨。 相似文献
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Hana Krýsov Josef Krýsa Kateina Macounov Jaromír Jirkovský 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1998,72(2):169-175
The photocatalytic degradation of diuron in aqueous solution on TiO2 layer of a batch mode plate reactor irradiated with ultraviolet sun-bed tubes was investigated. Dependence of the reaction rate on the diuron concentration (in the range of 0·8–8·0×10−5 mol dm−3) and on the light intensity (0·8–2·7×10−9 einstein cm−2 s−1) but independence on the flow rate (2·5–3·6 dm3 min−1) were found. A reaction scheme was proposed following the main identified primary [3-(3,4-dichlorophenyl)-1-methyl-1-formylurea and 3-(3,4-dichlorophenyl)-1-methylurea] and secondary [3-(3,4-dichlorophenyl)-1-formylurea and 3,4-dichlorophenylurea] products. © 1998 SCI 相似文献
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抗生素是治疗各种传染病的常用药物,但残留在水环境中的抗生素会对生态系统造成威胁。因此,探索去除水环境中抗生素的有效方法具有重要意义。由于光催化臭氧氧化技术可以高效降解和矿化水体中的污染物,该技术受到广泛关注。本工作通过浸渍-化学还原法制备Cu2O/TiO2复合材料并将其作为可见光催化臭氧氧化头孢曲松钠(CRO)的催化剂。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、比表面积分析仪(BET)和紫外-可见漫反射光谱仪(UV-Vis DRS)对Cu2O/TiO2形貌结构和光学性能进行表征,考察了Cu2O/TiO2配比、Cu2O/TiO2投加量、臭氧浓度、头孢曲松钠初始浓度、溶液初始pH值等因素对可见光催化臭氧氧化头孢曲松钠的影响。结果表明,Cu2O对TiO2的掺杂改性使材料孔容和平均孔径增大,能带宽度减小,... 相似文献
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采用固相法合成了锶掺杂二氧化钛(Sr-TiO2)介孔材料。采用XRD、TEM、UV-Vis、BET、Raman等测试手段对材料进行了详细表征,考察了材料对邻硝基苯酚的光催化活性。结果表明,Sr-TiO2材料为锐钛矿相,典型样品的BET比表面积为160.9 m2/g,孔径集中分布在7.2 nm处。锶的掺杂使TiO2晶体结构产生微小畸变,吸收带边发生红移;在紫外光照射下,Sr-TiO2对邻硝基苯酚的催化降解性能比纯TiO2有明显提高,2 h内光催化降解率达到98.2%。在邻硝基苯酚初始质量浓度为30 mg/L,催化剂投加量为1.2 g/L,光催化效率最高。 相似文献
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以强酸性控制水解法制备了纳米TiO2,结合XRD表征,研究了其悬浊液对含阳离子艳红5GN的模拟染料废水进行光催化降解的活性和规律.结果表明:在强酸性控制水解法中,500 ℃焙烧纳米TiO2催化剂具有最高催化活性,对比沉淀法和sol-gel法制备的纳米TiO2,其对阳离子艳红的降解速率提高了1.34倍和2.81倍;实验确定的优化降解条件为:6 W紫外光照、阳离子艳红5GN初始质量浓度为20 mg/L、催化剂投加量为1.5~2.0 g/L和空气曝气器功率2.50 W,此时阳离子艳红5GN在1 h内的降解率>90%;在阳离子艳红5GN初始质量浓度为10~40mg/L时,其降解过程遵循一级反应规律. 相似文献
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Fe2O3/TiO2纳米材料的制备及其紫外-可见光催化性能 总被引:5,自引:0,他引:5
采用溶胶-凝胶法制备了不同Fe含量的纳米Fe2O3/TiO2复合光催化材料,并用X射线衍射和透射电镜研究了样品的晶体结构和形貌,分别在紫外和可见光下研究了不同Fe含量复合催化剂的光催化降解甲基橙的活性.结果表明在Fe复合比例较低时,样品为锐钛矿结构;在紫外光情况下,最佳Fe2O3/TiO2复合比例为0.5%,在比例为10%情况下催化效果也比较好;而在可见光情况下,最佳fe2O3/TiO2复合比例为0.1%. 相似文献
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分别用花粉和柠檬酸为模板剂制得了光催化剂TiO2(HF)和TiO2(NM),并在紫外光下进行龙胆紫、蕃红花T、罗丹明B水溶液染料的降解实验。通过2 h的降解,用柠檬酸为模板剂制得的TiO2对蕃红花T染料的降解率达到77%,对罗丹明B染料的降解率达到了88%,对龙胆紫的降解率达到了90%,而用花粉为模板剂制得的TiO2对蕃红花T染料的降解率达到67%,对罗丹明B染料的降解率达到了37%,对龙胆紫的降解率达到了56%。结果显示,用柠檬酸为模板剂制得的TiO2的降解效果比用花粉为模板剂制得的TiO2明显得多,即前者的催化效率高于后者。 相似文献
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To study the effectiveness of photosensitizers to accelerate the degradation of cellulose acetate (CA) under ambient environment, CA (degree of substitution = 2.45) films containing benzophenone, which is one of the typical photosensitizers, were prepared and their degradative behavior by photoirradiation was examined. Decrease in molecular weight of CA and generation of carbon dioxide, carbon monoxide, and acetic acid from the CA films were observed by the irradiation of xenon arc lamp light, which was passed through a filter for cutting off the wavelength shorter than 275 nm. With increasing the concentration of benzophenone, the molecular weight of CA decreased and the generation of the degradation products from the CA films increased. These results may suggest that radical reactions of CA films proceed by photoirradiation and lead to oxidation and random cleavage of CA, and that benzophenone is an effective additive to accelerate the degradation of CA under ambient environment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
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以承德钢铁公司含钛高炉渣以及石英、硼酸、硼砂为主要原料,将配料组成选择在Na2O-CaO-Al2O3-B2O3-SiO2-TiO2系的分相区域,其中炉渣质量分数为50%~72%。将混合均匀的配料在1 250 ℃高温厢式电阻炉中熔融制得玻璃样品,对玻璃样品在700~900 ℃进行热处理制备二氧化钛晶须。用X射线衍射(XRD)、扫描电镜(SEM)对样品进行物相和形貌分析,结果表明:热处理温度为850 ℃时析出直径为0.5~1 μm、长径比大于50的钛酸钙(CaTiO3)晶须。样品组成中氧化钠的含量对钛酸钙晶须的生成影响较大,氧化钠的引入导致[BO3]向[BO4]转变,促进系统分相,使分相界面增多,提供了有利的成核位,促进了晶须的生长。样品的光催化效率最高可达58%。 相似文献
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采用共沉淀法制备了Mo/N共掺杂TiO2光催化剂(Mo-N-TiO2)。结果表明,所得光催化剂为锐钛矿晶型,Mo/N共掺杂使样品对可见光吸收增强,吸收带边明显红移。在Mo∶N∶Ti摩尔比为0.012 5∶0.02∶1,煅烧温度为500℃的最优制备条件下,样品在白炽灯下照射2 h对亚甲基蓝溶液脱色率达55.7%。Mo以+6价的形式存在,并取代Ti4+进入TiO2晶格中,导致TiO2表面的Lew is酸性增强,有利于其导带中光生电子向表面迁移,促进了光生电子-空穴对的分离,同时与共掺杂引起的带边红移和较完整的锐钛矿相的协同作用有效提高了TiO2的可见光催化活性。 相似文献
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TiO2粉末纳米尺寸效应对光催化性能的影响 总被引:3,自引:0,他引:3
用溶胶一凝胶法制备了TiO2纳米粉晶。对TiO2干凝胶粉进行了差热-热重(DTA/TG)分析;对不同温度处理的粉末用X射线衍射(XRD)进行了研究,并进行了比表面积测试。研究发现随着热处理温度的升高,纳米粉末的粒径逐渐增大,比表面积逐渐减小:晶型由锐钛矿变为金红石相。本实验通过光催化降解甲基橙来表征粉末的光催化活性。结果表明,TiO2纳米粉末的粒径、比表面积及晶型严重影响其光催化活性。另外,实验还发现TiO2纳米粉末对于光催化活性存在一个临界尺寸(约lOnm),当粉末的粒径小于这个临界尺寸时,其比表面积和光催化活性急剧增大。 相似文献
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以尿素铁(Ⅲ)配合物和钛酸四丁酯为前驱物,采用注入法制备了不同Fe2O3复合比的TiO2纳米粉体,通过DTATG 、XRD、XPS和UV-Vis的测试,表征其物相结构、样品表面元素存在形式和光谱学性质;并以甲基橙光降解反应为探针反应,分别以紫外光和可见光为光源测试其光催化活性.结果表明,复合Fe2O3后的TiO2纳米粉体为锐钛矿型,样品表面铁元素主要以Fe(Ⅲ)形式存在,并且其UV-Vis光谱吸收曲线有明显的红移现象;Fe2O3的复合明显提高了TiO2光催化剂的紫外和可见光催化活性;Fe2O3的最佳复合比为1 mol%. 相似文献