TiO_2-Al_2O_3负载型催化剂的制备及其光催化性能

以钛酸四丁酯和氢氧化钠为反应物,采用两步水热法制备TiO2纳米线,并将其原位负载于Al2O3载体上,研究它们对甲基橙的光催化降解性能。结果表明,锐钛矿相TiO2主要呈纳米线和八面体状负载在Al2O3载体上,当TiO2负载质量分数为30%,焙烧温度为400℃,催化剂用量为1.332 0 g/L时,TiO2-Al2O3负载型催化剂光催化降解甲基橙的性能最佳,光照5 h后,甲基橙在紫外和太阳光下的降解率分别达到58.9%和55.6%。相同实验条件下,TiO2-Al2O3负载型催化剂对甲基橙的降解率比单纯TiO2提高了35.1%。     

分光光度法研究膨润土负载CaSnO_3催化剂对甲基橙溶液的光降解性能

采用水热合成法制备出膨润土负载CaSnO3催化剂,以甲基橙溶液作为目标降解物,并对其光催化性能进行了研究。结果表明:膨润土负载CaSnO3催化剂对甲基橙溶液有较好的光催化降解效果。当催化剂浓度为0.06mol/L,膨润土负载量为3%时,降解率可达95%以上。     

TiO2/Hβ光催化剂的制备及性能研究

以钛酸丁酯为钛源,Hβ分子筛为载体,采用溶胶-凝胶法制备了负载型TiO2/Hβ复合光催化剂,并以甲基橙为模型反应物评价光催化剂的性能。结果发现,催化剂适宜的制备条件是:钛酸丁酯用量为10mL,蒸馏水加入量为3.0mL,乙醇水溶液pH值为3,焙烧温度为500℃。当用4.8g/L催化剂样品处理20mg/L的甲基橙溶液时,降解率为88.7%。     

两步法合成磷酸银及其光催化性能研究

采用两步法制备磷酸银光催化剂并用于可见光下降解甲基橙。结果表明,两步法合成磷酸银光催化性能优于一步沉淀法,10min甲基橙降解率可达98%。磷酸银光催化降解甲基橙最佳条件为:催化剂量为2.5g/L,反应时间10min,光强16Klux。表征结果表明,磷酸银为简单立方晶型,颗粒尺寸为1μm,吸收边为535nm,光照后表面吸附羟基自由基。重复性实验证明磷酸银光稳定性差,6次重复使用其10min甲基橙降解率降至12.85%,XRD结果证实磷酸银表面产生单质银。     

光还原法制备纳米Ag/ZnO及其光催化性能研究

采用光还原法制备了Ag/ZnO光催化剂,并运用紫外-可见光谱、X射线衍射、扫描电子显微镜和透射电子显微镜对催化剂进行表征。以甲基橙为标志物,探究了催化剂的投加量和甲基橙的初始浓度对光催化反应性能的影响。结果表明:Ag~+成功的进入了ZnO晶格中,取代了部分Zn~(2+)。光催化降解反应表明,Ag/ZnO都能够提高光催化效率,当催化剂用量为1.2g/L,光照30min,可以使0.01g/L的甲基橙溶液降解率达到92.259%。     

壳聚糖-CdS复合纳米粒子对甲基橙的光催化降解作用

用反相微乳液法制备了壳聚糖-CdS复合纳米粒子,并考察了复合纳米粒子用量、光照条件和溶液pH值等因素对光催化降解甲基橙的影响.结果表明:在100 mL质量浓度为20 mg/L的甲基橙溶液中加入0.30 g复合纳米粒子,可以达到较好的光催化降解效果;甲基橙在光催化降解过程中最大吸收波长464 nm处的吸收峰迅速减弱,并最终消失,且在258 nm和455 nm处出现了新的吸收峰,说明甲基橙发生了降解;溶液pH值对光催化降解甲基橙有一定的影响,在弱酸性条件下降解效率较高;复合纳米粒子比普通CdS降解效率高,2 min时高出50%,400 min时高出21.3%.初步提出了复合纳米粒子光催化降解机理,复合纳米粒子的吸附作用是光催化降解作用的前置步骤.     

TiO2纳米棒光催化降解甲基橙的研究

本文以甲基橙为目标降解物考察了催化剂的添加量、甲基橙溶液的pH值、晶化时间、热处理温度等因素对用"软模板"制备的TiO2纳米棒光催化活性的影响.研究表明:当催化剂添加量为0.08g、甲基橙溶液的pH=4、晶化时间为24h、热处理温度为500℃时,TiO2光催化剂的催化效果最佳,达到了85.96%.     

镁酞菁/PHBV催化薄膜的制备及光催化性能研究

将四氨基镁酞菁(MgPc)负载到PHBV上制备复合催化薄膜(MgPc/PHBV)。采用XRD、FT-IR、TGDTA和UV-Vis DRS等表征技术对MgPc/PHBV的结构和性质进行表征。结果表明,MgPc和PHBV之间可能通过物理作用结合;MgPc的加入降低PHBV的结晶度;并且将PHBV的分解温度提高20℃。基于UV-Vis DRS的测试表明MgPc/PHBV薄膜具有可见光催化活性。此外,MgPc/PHBV光催化降解有机污染物甲基橙的结果表明,光照、MgPc/PHBV和H_2O_2同时存在时才能催化氧化甲基橙;光照160 min后,甲基橙剩余率为0.0%,甲基橙完全被降解。光催化氧化反应中羟基自由基发挥着关键作用。     

纳米四针状氧化锌晶须光催化降解甲基橙

以纳米四针状氧化锌晶须(T-ZnOw)为光催化剂,以甲基橙为染料模型化合物,研究了T-ZnOw的光催化氧化降解性能.考察了甲基橙溶液的初始浓度、催化剂用量和粒径等因素对光催化氧化降解反应的影响.研究结果表明,纳米T-ZnOw光催化氧化降解甲基橙的反应遵循一级反应动力学规律;光催化剂纳米T-ZnOw的最佳用量为2g/L,此时经60min光催化降解后,甲基橙溶液的色度剩余率仅为8%;T-ZnOw粒子直径越小,光催化活性越高,效果越好.对比实验和重复实验结果表明,纳米T-ZnOw的光催化氧化降解效果比纳米TiO2和普通球形纳米ZnO粉体更好,是一种高效、长寿的光催化剂材料.     

细菌纤维素负载TiO_2复合材料的制备及其在印染废水处理方面的应用

利用细菌纤维素超细高强的特点,原位制备细菌纤维素/TiO2纳米复合材料,并对其表面化学组成和微观结构进行表征。利用细菌纤维素负载TiO2纳米粒子用于染料废水的处理,具有处理效果好、可以多次反复使用等优点。结果表明:紫外光催化降解后,复合材料对甲基橙溶液的降解率可达到100%。重复4次降解后,最大降解率仍有51.8%。     

铁/镱掺杂二氧化钛空心球的制备及其光催化性能

用模板法制备铁/镱共掺杂二氧化钛空心球(Fe/Yb-TiO2HS),使用扫描电子显微镜(SEM)观察和X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶红外光谱(FT-IR)、热失重(TG)等测试方法对对其进行了表征.使用浓度为20 mg/L的甲基橙溶液模拟废水,研究了铁/镱共掺杂二氧化钛空心球的催化性能.结果 ...     

Enhanced photocatalytic activity of ZnO/CuO nanocomposite for the degradation of textile dye on visible light illumination

The photocatalytic degradation of organic dyes such as methylene blue and methyl orange in the presence of various percentages of composite catalyst under visible light irradiation was carried out. The catalyst ZnO nanorods and ZnO/CuO nanocomposites of different weight ratios were prepared by new thermal decomposition method, which is simple and cost effective. The prepared catalysts were characterized by different techniques such as X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and UV–visible absorption spectroscopy. Further, the most photocatalytically active composite material was used for degradation of real textile waste water under visible light illumination. The irradiated samples were analysed by total organic carbon and chemical oxygen demand. The efficiency of the catalyst and their photocatalytic mechanism has been discussed in detail.     

WO_3-TiO_2纳米材料的制备及其光催化性能

采用溶胶-凝胶法制备WO3-TiO2纳米复合材料,并用透射电镜和X射线衍射对所制备材料进行表征和分析。以WO3-TiO2纳米材料为光催化剂对甲基橙进行光催化降解处理,研究WO3的掺杂量、煅烧温度、光照时间等因素对甲基橙降解率的影响。结果表明:在紫外灯照射下,使用w(WO3)=3%、550℃下煅烧得到的WO3-TiO2纳米复合粉体0.02 g,甲基橙溶液20 mL(ρ=5 mg/L,pH=4),光催化3 h后,甲基橙降解率达到94.93%。     

Synthesis of PANI/TiO<Subscript>2</Subscript>–Fe<Superscript>3+</Superscript> nanocomposite and its photocatalytic property

A convenient method for synthesizing highly photocatalytic activity PANI/TiO₂–Fe³⁺ nanocomposite was developed. The effect of calcination temperature on the phase composition of TiO₂ nanopowder was investigated. It was found that higher temperature could promote the formation of rutile phase. The nanocomposite was characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), infrared spectroscopy (IR) and X-ray diffraction (XRD). The results indicated that the nanohybrid was composed of TiO₂, Fe³⁺ and PANI. The photocatalytic property of the nanocomposite was evaluated by the degradation of methyl orange. In the presence of this catalyst, the degradation rate of methyl orange of 95.2% and 70.3% could be obtained under the UV and sunlight irradiation within 30 min, respectively. The apparent rate constant was 5.64 × 10⁻² which is better than that of the Degussa P25.     

Synthesis of [60]fullerene-ZnO nanocomposite under electric furnace and photocatalytic degradation of organic dyes

Zinc oxide (ZnO) nanoparticles were synthesized by a reaction between an aqueous-alcoholic solution of zinc nitrate and sodium hydroxide under ultrasonic irradiation at room temperature. The morphology, optical properties of the ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis spectroscopy. The [60]fullerene and zinc oxide nanocomposite were synthesized in an electric furnace at 700 degrees C for two hours. The [60]fullerene-ZnO nanocomposite was characterized by XRD, SEM and TEM. In addition, the [60]fullerene-ZnO nanocomposite was investigated as a catalyst in the photocatalytic degradation of organic dyes using UV-vis spectroscopy. The photocatalytic activity of the [60]fullerene-ZnO nanocomposite was compared with that of ZnO nanoparticles, heated ZnO nanoparticles after synthesis, pure [60]fullerene, and heated pure [60]fullerene in organic dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under ultraviolet light at 254 nm.     

Photodegradation of methyl orange by photocatalyst of CNTs/P-TiO(2) under UV and visible-light irradiation

A novel nanoscale photocatalyst CNTs/P-TiO(2) was successfully prepared by hydrothermal method. The morphology and the physicochemical properties of the prepared samples were investigated using TEM, XPS, XRD, BET, FTIR, TG-DSC and UV-vis DRS spectroscopy. The photocatalytic activity was evaluated by degradation of methyl orange (MO) dye. The results demonstrated that CNTs/P-TiO(2) nanoparticles could effectively photodegrade MO not only under UV irradiation but also under visible-light (VL) irradiation. The MO degradation performance on CNTs/P-TiO(2) was superior to that of the commercial P25. The optimal mass ratio of CNTs to P-TiO(2) in the nanocomposite catalyst was 5:100. The synergetic effect was discussed in terms of different roles played by phosphorus doping and introducing CNTs into the composite catalysts.     

不同形貌纳米CdS的合成及超声催化H2O2降解甲基橙

采用水热法,通过参数调控合成了三种形貌的CdS纳米晶,并采用SEM、XRD、EDS对产物的形貌、结构、成分进行了表征,将其应用于超声（US）催化H2O2氧化降解甲基橙,考察温度、H2O2加入量、pH以及不同形貌纳米晶对甲基橙降解的影响,结果表明,在pH为5.98、浓度为10mg/L的甲基橙溶液中加入1mL浓度为30%H2O2和20mgCdS纳米晶,在25℃环境中超声10min,三种形貌的CdS纳米晶催化降解甲基橙均可达90%左右。     

TiO2纳米颗粒的制备、光催化性能及羟基自由基研究

采用聚丙烯酰胺凝胶法制备了TiO2纳米颗粒,利用X射线衍射、扫描电子显微镜和紫外．可见光漫反射光谱分别研究了不同煅烧温度对样品晶相、颗粒形貌和带隙的影响．以甲基橙（M0）为目标降解物,在紫外光照射下考察了制得的TiO2样品的光催化性能．研究结果表明,500℃煅烧制备的样品光催化性能最好;随着催化剂用量的增加,MO降解率呈现先增大后减小的趋势,最佳催化剂用量为4．0g／L;在pH值不太高时（≤7．2）,M0降解率随pH值的升高呈下降趋势．以香豆素为探测剂．采用荧光光谱检测催化剂在紫外光照射下产生羟基自由基（·OH）的情况,研究了煅烧温度、催化剂用量和溶液pH值对·0H产率的影响．研究结果还表明,·OH产率与MO降解率的变化规律基本一致,表明·0H可能是TiO2光催化降解有机染料的主要活性物种．     

纳米二氧化锰负载钴锰催化K_2S_2O_8/NaHCO_3降解甲基橙

为了去除碱性水溶液中的染料,采用纳米二氧化锰负载钴锰(Co(Ⅱ)-Mn(Ⅱ)-MnO_2)催化K_2S_2O_8/NaHCO_3氧化降解染料。对Co(Ⅱ)-Mn(Ⅱ)-MnO_2催化剂进行形貌和结构表征。考察了溶液初始pH值、反应温度、催化剂投加量、甲基橙(MO)、过硫酸钾摩尔比及碳酸氢钠浓度等因素对Co(Ⅱ)-Mn(Ⅱ)-MnO_2催化氧化MO的影响,并对MO氧化过程结构变化进行分析。实验结果表明:在优化条件下Co(Ⅱ)-Mn(Ⅱ)-MnO_2催化MO(40mg/L)的降解率达到82.61%,MO降解反应动力学为一级反应。该体系适合处理中性和弱碱性MO废水。