ZnO/WO_3纳米片薄膜的光电催化性能研究

采用水热法在不锈钢基底上制备WO3纳米片阵列,然后将其浸渍于不同浓度Zn(NO_3)_2溶液中以负载ZnO纳米颗粒,从而制备出ZnO/WO_3纳米片薄膜。采用场发射扫描电镜(FESEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外-可见吸收光谱(UV-Vis)和电化学阻抗图谱(EIS)等方法对ZnO/WO_3复合薄膜的形貌、结构、物相组成和光电性能等进行分析,重点考察了薄膜电极对亚甲基蓝(MB)的光电催化降解性能。结果表明,WO_3纳米片均匀垂直于基底生长,Zn元素以ZnO颗粒的形式分布在WO_3表面;ZnO的引入促进了WO_3中产生的光生电子-空穴对的分离,从而使ZnO/WO_3复合薄膜表现出比纯WO_3薄膜更优异的光电性能和光电催化活性;在Zn(NO_3)_2浸渍液浓度为20mmol/L时,所制ZnO/WO_3复合薄膜具有最佳的光电催化性能,在MB溶液初始浓度为10mg/L、外加偏压为0.8V、光照1h的条件下,采用该样品对MB的降解率达96.5%,并且复合薄膜具有良好的循环稳定性,在重复使用5次后,对MB的光电催化降解效率没有明显降低,有望在实际污水处理中得到应用。     

可见光响应型石墨烯/氧化铈复合材料的制备及性能

采用水热法在不同的温度条件下制备了石墨烯/氧化铈复合粉体.通过XRD,SEM,TEM,TG,UV-vis光谱仪等分析手段对产物的结构和形貌进行了表征,并以甲基橙溶液为模拟废水,测试了所得到的催化剂在可见光照射下的光催化性能.研究结果表明:制备温度影响了复合材料的组成和结构;140℃制备所得样品,其石墨烯表面修饰的氧化铈含量最高,颗粒尺寸在20 nm左右,并且分布均匀.同时所制备出的石墨烯/氧化铈复合粉体对降解甲基橙表现出了良好的光催化活性.UV-vis和光电流分析表明,复合粉体表现出良好的可见光吸收能力和光生电子-空穴分离能力.     

铁酸铋的制备及其在废水中的应用研究进展

有机污染是当今社会最主要的环境问题之一,光催化降解有机污染物是一种新型高效的处理方法。BiFeO3是目前唯一的一种在室温下具有铁电性和铁磁性的单相多铁材料,具有窄的带隙与良好的可见光吸收性能,可以将有机污染转换为无毒无害的形式,或完全降解为 CO2 和 H2O。BiFeO3的优良性能,使之在光催化领域有着广阔的应用前景,是研究者的重点关注方向。本文综述了近几年BiFeO3光催化材料常用的制备方法以及其在废水处理中的应用;概述了BiFeO3催化剂的改进(离子掺杂、半导体复合、贵金属沉积等)和反应条件的优化(光源、pH、催化剂浓度等)这两个方面在提高其光催化效果的研究进展;最后总结了BiFeO3材料在废水处理中存在的问题,并对今后的研究进行了展望。     

WO3-ZrO2/SBA-15的制备及其可见光催化分析

通过溶胶凝胶法,分别制备了不同负载量的WO_3/SBA-15和WO_3-ZrO_2/SBA-15介孔材料,利用XRD、BET和TEM等表征手段对其进行表征,并对其光降解染料罗丹明B的活性进行比对研究分析。结果表明:Wx/SBA-15(x=20,30,40,50)和W_(40)Zry/SBA-15(y=3,5,7,9)均能在可见光下光降解罗丹明B,光催化活性W_(40)/SBA-15W_(50)/SBA-15W_(30)/SBA-15W_(20)/SBA-15;引入ZrO_2后,光催化活性W_(40)Zr_5/SBA-15W_(40)Zr_9/SBA-15W_(40)Zr_7/SBA-15W_(40)Zr_3/SBA-15。其中,W_(40)/SBA-15和W_(40)Zr_5/SBA-15的光降解效率最高,分别为73.4%和86.6%,ZrO_2的引入提高了光降解效率;同时,WO_3/SBA-15和WO_3-ZrO_2/SBA-15也具有很好的循环价值,可多次使用。     

过渡金属离子改性TiO2薄膜上甲醛光催化降解作用研究

用溶胶-凝胶法在玻璃表面制备了不同金属离子掺杂的TiO2光催化薄膜，考察了掺杂金属离子种类（Fe^3＋、Cd^2＋、Cr^3＋、Co^2＋等）及其掺杂量对TiO2薄膜光催化降解甲醛的影响。结果表明，在日光灯和紫外灯照射下，各种溶胶体系所制备的催化荆均具有一定的甲醛降解活性，其中以添加乙酰丙酮缓释剂的溶胶体系所制备的催化剂活性较好。在掺杂的各种过渡金属离子中，掺杂Cd^2＋1．5wt％的TiO2薄膜催化剂表现出最好的甲醛光催化降解性能。XRD研究表明催化剂中的TiO2主要为锐钛矿型，掺杂Cd^2＋1．5wt％的样品的DR UV-VisiO2在430nm和600nm处出现宽的吸收峰，与该催化剂在日光灯照射下具有相对高的甲醛降解活性结果相吻合。     

TiO_2纳米棒薄膜的水热法制备及光催化性能研究

本文以钛酸四丁酯为原料,采用水热法在FTO导电玻璃上制备了TiO_2纳米棒薄膜,应用SEM和XRD对膜层的形貌和晶型进行了分析和表征,并通过TiO_2纳米棒薄膜对甲基橙的光催化降解,研究了TiO_2纳米棒薄膜的制备条件与光催化活性的关系。结果表明:增加钛酸四丁酯的浓度和提高水热温度,都会提高样品的结晶程度,增加金红石相TiO_2的组分,使薄膜对紫外线的吸收明显增强,光催化性能显著提高。用该法制备的TiO_2纳米棒薄膜均匀、致密、无可视缺陷、稳定性好,光催化效率高,并且不产生二次污染,具有广泛的应用前景。     

具有光催化活性的纳米TiO2的制备

以Ti(OC4H9)4为原料,采用Sol-gel法制备TiO2溶胶,通过浸渍提拉法涂覆在玻璃(或陶瓷)片上,可以得到晶粒为12.5～18.7nm的纳米薄膜,这种涂膜具有较强的光催化活性.以TiCl4为原料,采用水热沉淀法制备的纳米TiO2粉体,具有粒径为10.3～25.7nm,437m2/cm3的巨大比表面.     

WO_3/BiVO_4薄膜光电极构建及光电转化性能

分别用聚合物辅助沉积法和金属有机物分解法制备了WO_3和BiVO_4半导体薄膜电极。利用固体紫外-可见漫反射光谱、电化学阻抗和线性扫描伏安法,对WO_3和BiVO_4半导体薄膜电极的能带结构进行了表征。制备了WO_3/BiVO_4异质结复合光电极,并通过扫描电子显微镜、X射线衍射和X射线光电子能谱,对该复合光电极的断面形貌、晶型结构和物质组成进行了分析。最后,对WO_3/BiVO_4复合光电极的光电转化性能进行了研究。研究结果表明:均为单斜晶型的WO_3和BiVO_4之间形成了膜厚约为450 nm的II型异质结;在施加相对于可逆氢电极1.23 V的电势时,WO_3/BiVO_4光电极的光电流密度可以达到1.926 m A/cm~2,表现出了良好的光电转化性能。     

ZnO光催化剂的制备及改性方法的研究进展

作为一种半导体功能材料,ZnO具有低毒、原料廉价、易制备及改性等突出特点.由于ZnO禁带较宽、载流子复合率高,在太阳光照射下的催化活性并不高,需要采用相关技术对其进行科学改性.目前,如何采用科学方法进行ZnO光催化剂的制备与改性一直备受科研人员的关注.通过制备方法的改进、元素掺杂、半导体复合及模板剂的引入等技术手段均可以提高ZnO的光催化活性.分析了ZnO光催化的机理、ZnO的制备方法以及掺杂、复合等提高其光催化活性的方法,旨在为今后进一步拓展ZnO光催化材料的研发及应用提供新的思路.     

锐钛矿型TiO_2薄膜的研究进展

二氧化钛薄膜是一种重要的半导体材料,在传感器、光催化和太阳电池等领域具有广阔的应用前景.二氧化钛薄膜的制备方法决定了其物相结构、物理化学性质、光学和电学特性.简要介绍了二氧化钛的物相结构,综述了锐钛矿型二氧化钛薄膜的制备方法,分析讨论了它们各自的优缺点,展望了其未来的发展趋势.     

光还原法制备Ag/Bi2WO6可见光催化剂及其性能研究

利用离子液体辅助醇热法制备了具有较高活性的Bi_2WO_6可见光催化剂,并进一步采用光还原法将Ag纳米粒子负载到Bi_2WO_6催化剂表面.利用Ag良好的导电性以及表面plasma效应,有效增强了催化剂的可见光吸收,降低了光生载流子复合的几率,显著提高了污染物降解的光催化活性.同时确定了最佳Ag含量和反应条件.     

光降解用WO_3-TiO_2复合光催化剂

用溶胶 凝胶法制备了纳米WO3 TiO2复合薄膜型光催化剂·利用该薄膜对罗丹明B溶液的光催化降解作用,考察了钨酸盐种类及其掺杂量、涂膜层数、溶解氧、焙烧温度、焙烧时间、基体材料等因素对光催化活性的影响·结果表明,钨酸铵加入量x(W)=1 5%、多孔钛片为基质,涂覆9层、500℃下焙烧1h得到的WO3 TiO2薄膜型复合光催化剂活性最高,其光催化活性较纯TiO2光催化剂提高1 5倍·该温度下多孔钛片负载的TiO2为锐钛矿型·     

Preparation and photocatalytic properties of ilmenite NiTiO<Subscript>3</Subscript> powders for degradation of humic acid in water

The powders of ilmenite structure NiTiO₃ were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA) and X-ray diffraction (XRD). The photocatalytic activity of NiTiO₃ under the irradiation of ultraviolet rays (UV) light was evaluated by degrading humic acid (HA) in water as a probe reaction. The possible photodegradation mechanism was studied by the examination of active species ·OH, ·O₂⁻, and holes (h⁺) through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO₃ could be obtained when the Ni-Ti citrate complex was calcined at 600°C. The photocatalytic activity experiments indicated that NiTiO₃ had favourable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradation rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600°C and a photocatalyst dosage of 0.4 g/L. The possible photocatalytic mechanism was deduced that holes (h⁺) and ·OH radicals are the major reactive active species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA.     

Enhanced photocatalytic degradation of tetracycline hydrochloride by molecular imprinted film modified TiO<Subscript>2</Subscript> nanotubes

To enhance the photocatalytic activity of TiO2 nanotubes,tetracycline hydrochloride(TC) molecularly imprinted titania modified TiO2 nanotubes(MIP-TiO2) was prepared by liquid phase deposition,which improved the molecular recognition ability of the photocatalyst toward template molecules.This MIP-TiO2 photocatalyst was characterized by ESEM and XRD,which showed that the imprinted titania was deposited on the nanotube uniformly and was of well-crystalized anatase-type.In the adsorption experiments,MIP-TiO2 exhibited a high adsorption capacity(about 1.6 times higher than that of TiO2 nanotubes) for TC mainly because of its imprinted sites and high surface area.Under UV irradiation MIP-TiO2 showed enhanced photocatalytic activity with an apparent first-order rate constant 1.9-fold that of TiO 2 nanotubes.     

Synthesis of magnetically recoverable visible-light-induced photocatalysts by combination of Fe_3O_4/ZnO with BiOI and polyaniline

Magnetically recyclable photocatalysts with efficient performances under visible light were synthesized by combining Fe_3O_4/ZnO with BiOI and polyaniline(PANI). The FT-IR, XRD, HRTEM, SEM, EDX, XPS, UV–vis DRS,VSM, BET, and PL instruments were utilized for characterization of the as-prepared products. The activity tests exhibited that the superior rate constant in photocatalytic performance was achieved over the Fe_3O_4/ZnO/BiOI/PANI(20%) nanocomposite, which enhanced for more than 59.9, 10.0, and 6.57 times, as compared to those of the Fe_3O_4/ZnO, Fe_3O_4/ZnO/PANI, and Fe_3O_4/ZnO/BiOI photocatalysts in degradation of RhB, respectively.Successful photocatalytic degradations of MO/MB and photo reduction of Cr(VI) were also investigated to confirm the potential application of the photocatalyst in removal of various pollutants. The considerably enhanced activity pointed to a promoting effect of p-n-p heterojunctions formed between PANI, ZnO, and BiOI, and improved textural characteristics, which are benefit for improvement of the photocatalytic performances.     

基于正交实验法的WO3电致变色薄膜Li掺杂分析

单一纯净的WO₃电致变色薄膜的性能已经不能满足实际应用的需要,通过掺杂对薄膜性能进行提升已经成为WO₃电致变色薄膜研究领域的一个重要环节.笔者采用乙酸锂作为Li源进行Li掺杂,分析表明：Li掺杂后的WO₃薄膜性能得到了很大的提升,并对正交实验法的Li掺杂量进行了讨论.     

Depositing Ag3PO4 on WO3 hollow microspheres at room temperature for rapid photocatalytic degradation of Rhodamine B

A series of WO₃ hollow microspheres decorated with Ag₃PO₄ nanoparticles (APW) composites with Ag₃PO₄:WO₃ mass percentage of 20% (20APW), 30%(30APW), 40%(40APW) and 50% (APW) were successfully synthesized, characterized and tested for the degradation of the Rhodamine B(RhB) under 300 ?W xenon lamp radiation. The photocatalytic results showed that the photocatalytic degradation performances of WO₃ hollow microspheres decorated with Ag₃PO₄ nanoparticles on RhB were significantly enhanced, which were much higher than that of individual Ag₃PO₄ and WO₃. Especially for 40APW, RhB can be completely degraded within 10 ?min. The order of degradation efficiency is 20APW<50APW< 30APW<40APW. The rate constant of 40APW (0.3902 min^?1) is about 81.3 times that of WO₃ (0.0048 min^?1). The diffuse reflection, photoluminescence and electrochemical impedance tests showed that the formation of Ag₃PO₄/WO₃ composite structure broadened the light absorption range, reduced the recombination rate of photogenerated electrons and holes, and decreased the resistance to charge transfer, which are beneficial to the improvement of photocatalytic performance. The capture agent experiments were carried out with 40APW, which specified the primary role of h⁺ and ?O₂^? in the degradation of RhB. The formation of heterojunction between Ag₃PO₄ and WO₃ that effectively separates photogenerated electrons and holes are contributed to the enhancement of photocatalytic properties of APW composites.     

Carboxyl-modified hierarchical wrinkled mesoporous silica supported TiO2 nanocomposite particles with excellent photocatalytic performances

Titanium dioxide (TiO₂) is a common photocatalyst for organic pollutants degradation. However, in practical application, the poor adsorption capacity of pure TiO₂ seriously impeded its efficiency in the degradation of organic molecules. In this work, a series of hierarchical wrinkle mesoporous silica supported TiO₂ nano-composite particles (TiO₂ @WMS-COOH) were successfully prepared. Thanks to their high surface areas, large pore volumes and mesoporous structures, these materials showed high adsorption capacity and excellent photocatalytic performance towards dye molecules, which is comparable to or even better than commercial catalyst P25. Moreover, their photocatalytic efficiency can be further enhanced by increasing the calcination temperature during preparation process. Therefore it can be concluded that the TiO₂ @WMS-COOH particles may find promising applications in the photodegradation of organic pollutants.     

热处理温度对TiO2薄膜光催化活性影响的研究

 采用溶胶-凝胶法及浸渍提拉法,在普通玻璃载玻片上制得了TiO₂薄膜,通过差热分析仪及X射线衍射仪分析了热处理温度对TiO₂的晶型、晶粒大小、孔隙率及薄膜的光催化活性的影响,结果表明存在一个最佳的热处理温度范围,在这一温度范围内薄膜的光催化活性最好.     

铝片TiO2薄膜在降解4BS染料中的应用

采用溶胶-凝胶(sol-gel)工艺在铝片表面制得了均匀透明的TiO2薄膜,考查了其光催化降解4BS染料的活性,研究了热处理温度、涂覆层数、以及溶液改性等因素对TiO2薄膜的光催化性能的影响.结果表明:该薄膜能有效降解4BS染料,热处理温度、涂覆层数影响薄膜的性能,层数为5,热处理温度为600 ℃的薄膜具有较高的光催化活性.TiO2薄膜对加入Fe3+的4BS溶液的降解率明显提高.