活性炭负载TiO2光催化降解1-萘胺

活性炭负载TiO2光催化降解1-萘胺;炭载TiO2光催化剂;萘胺;光催化降解     

活性炭孔径和比表面积对TiO2/AC光催化性能的影响

采用"同步物理-化学活化法"二次活化商品活性炭,制备不同孔径和比表面积的系列活性炭(AC)载体,以偏钛酸为钛源,利用均匀沉淀法制备TiO2负载型光催化剂(TiO2/AC),用氮吸附、XRD、SEM等方法表征,研究活性炭的孔径和比表面积对TiO2/AC性能的影响;并通过降解水溶液中的亚甲基蓝(MB)研究TiO2/AC光催化氧化特性,考察催化剂投加量、不同MB浓度等因素对光催化氧化的影响.结果表明,负载的TiO2粒子粒径为12-20 nm,活性炭的比表面积大、平均孔径大有利于TiO2的均匀分散,阻止TiO2晶粒生长,有利于充分发挥TiO2小尺度效应;另外,活性炭吸附和TiO2光解的协同效应使TiO2/AC光催化剂对MB降解的效率显著提高.动力学研究表明,TiO2/AC光催化降解MB反应符合表观一级动力学特征.     

活性炭孔径和比表面积对TiO2/AC光催化性能的影响

采用“同步物理-化学活化法”二次活化商品活性炭, 制备不同孔径和比表面积的系列活性炭(AC)载体, 以偏钛酸为钛源, 利用均匀沉淀法制备TiO2负载型光催化剂(TiO2/AC), 用氮吸附、XRD、SEM等方法表征, 研究活性炭的孔径和比表面积对TiO2/AC性能的影响; 并通过降解水溶液中的亚甲基蓝(MB)研究TiO2/AC光催化氧化特性, 考察催化剂投加量、不同MB浓度等因素对光催化氧化的影响. 结果表明, 负载的TiO2粒子粒径为12-20 nm, 活性炭的比表面积大、平均孔径大有利于TiO2的均匀分散, 阻止TiO2晶粒生长, 有利于充分发挥TiO2小尺度效应; 另外, 活性炭吸附和TiO2光解的协同效应使TiO2/AC光催化剂对MB降解的效率显著提高. 动力学研究表明, TiO2/AC光催化降解MB反应符合表观一级动力学特征.     

TiO2/AC复合光催化剂对苯和丁醛的气相光催化降解机理

 利用溶胶-凝胶并水热处理法制备了TiO2光催化剂和TiO2/AC复合光催化剂,在静态光催化反应器中研究了苯和丁醛的气相吸附和光催化降解,利气相色谱分析确定了生成的中间体. 结果表明, TiO2/AC复合光催化剂比TiO2光催化剂具有较强的吸附能力和较高的光催化活性; 在TiO2和TiO2/AC上,苯(或丁醛)光催化降解产生相同的中间体,表明在两种催化剂上发生的光催化反应遵循相同的机理,进而讨论了其可能的光催化氧化途径.     

TiO2/SnO2复合光催化剂的制备及光催化降解敌敌畏

包覆型催化剂;TiO2/SnO2复合光催化剂的制备及光催化降解敌敌畏     

Zn-TiO2/AC复合催化剂的制备及其光催化活性

以硝酸锌、钛酸四丁酯和活性炭为原料,采用真空吸附法制备了不同组成的Zn TiO₂/AC.通过X射线衍射(XRD)和透射电镜(TEM)对催化剂进行了表征.选择较难降解的Cl₃CCOOH作为探针分子考察了其光催化活性.结果表明,掺锌能提高TiO₂/AC的催化活性,当Zn的摩尔分数为0.5%(相对TiO₂)、处理温度为400℃,溶液的pH值为6时,Zn TiO₂/AC催化剂具有很好的光催化活性.     

玻璃负载TiO2膜光催化降解2,4-二氯苯酚

玻璃负载TiO2膜光催化降解2;4-二氯苯酚     

活性炭孔结构对TiO2/AC复合光催化剂光催化活性的影响

以4种表面化学性质相近, 而孔结构差异较大的活性炭(AC)为原料, 采用酸催化水解法合成了系列TiO2/AC复合催化剂, 考查活性炭孔结构对复合光催化剂活性的影响. 以苯酚为模型物, 考察了催化剂的活性;以低温(77 K)液氮吸附测定活性炭的比表面积、孔容和孔径分布;以Boehm滴定及元素分析定量表征活性炭表面化学性质. 以SEM观测复合催化剂表面TiO2的分散性能;以X射线衍射(XRD)、漫反射光谱(DRS)测试光催化剂晶相结构参数及光吸收阈值. 结果表明, 活性炭孔结构性质对TiO2/AC活性影响显著. AC1、AC2、AC3、AC4对TiO2活性提高的协同系数分别为1.55、2.03、1.28、1.43. 协同系数大小与接触界面面积变化值(⊿S)趋势相似. 具有发达的微孔及适量中孔结构的TiO2/AC复合光催化剂的催化活性最高.     

钒掺杂TiO2/AC负载催化剂的制备及光催化活性

以TiO2为主要成分的光催化剂的研究已日益受到人们的广泛关注[1-6]。但TiO2粉末的回收和流失问题难以解决,固定化TiO2负载催化剂的研制是解决这一问题的有效手段[2-6]。从实际应用的观点看,TiO2的光催化剂活性还有待进一步提高。研究发现,大多数过渡金属离子和少数非金属离子的     

负载型纳米TiO2光催化降解活性艳红X-3B染料

光催化氧化;负载型纳米光催化剂;负载型纳米TiO2光催化降解活性艳红X-3B染料     

空气电极/AC作载体对TiO2光催化性能的影响

The photo catalytic degradation of activated red in the aqueous solution was studied using TiO2 supported on air electrode and active carbon (AC) as photo catalysts. It was found that the photo catalytic reaction rate of TiO2 was obviously increased by the presence of air electrode and AC supported. The air electrode which has functions of synthesizing H2O2 in situ and photocatalysis was reported. The results also implied that biasing of the electrode at +0.5V led to efficient charge separation. The current density of air (oxygen) electrode had effect on the oxidation rate of azo dye molecule, i=15 mA/cm2, and the rate could reach maximum. With AC mass fraction of about 21% the oxidation rate for TiO2/AC was obviously larger than that for TiO2, but the result was contrary to this for higher AC mass fraction (>30%). The experiment results showed that because TiO2 was supported on active carbon, the effective surface area of the photo catalysis and their absorbability for organic molecules can be increased. The pH in solution had effect on the oxidation rate of organic molecules.     

TiO2/AC光催化剂上气体污染物降解的反应动力学模型

 利用二氧化钛与活性炭(AC)共水热处理的方法制备了TiO2/AC复合催化剂,采用空气净化评价装置对其催化降解低浓度气体污染物丁醛的性能进行了模拟评价实验. 基于Langmuir-Hindshelwood方程和一些假设,推导了循环反应系统气体污染物降解的瞬态模型. 结果表明,该动力学模型所得数据与丁醛的模拟评价实验结果基本相符,预示着该模型能够很好地预测污染物的降解行为.     

表面氟化TiO2空心光催化剂制备及其应用

Recently, extensive studies have been carried out to synthesize spherical microassemblies with hollow interiors and specific surface functionalizations, which usually exhibit fascinating enhanced or emerging properties and have promising applications in catalysis, photocatalysis, energy conversion and storage, biomedical applications, etc. With particular emphasis on the results obtained mainly by the authors' research group, this review provides a brief summary of the recent progress on the fabrication and potential photocatalytic applications of fluorinated TiO₂ porous hollow microspheres(F-TiO₂ PHMs). The synthesis strategies for F-TiO₂ PHMs include a simplified two-step templating method and template-free method based on the fluoride-mediated self-transformation(FMST) mechanism. Compared to the two-step templating method, the template formation, coating, and removal steps for the FMST method are programmatically proceeded in "black-box"-like one-pot reactions without additional manual steps. The four underlying steps involved in the fabrication of F-TiO₂ PHMs through the FMST pathway, nucleation, self-assembly, surface recrystallization, and self-transformation, are presented. By controlling these four steps in the FMST pathway, F-TiO₂ PHMs can be successfully fabricated with a high yield by a simple one-pot hydrothermal treatment. The multi-level microstructural characteristics(including the interior cavity and hierarchical porosity) and compositions of hollow TiO₂ microspheres as well as the primary building blocks can be well tailored. The unique superstructures of the F-TiO₂ PHM photocatalysts provide advantages for photocatalytic applications by improving the light harvesting, mass transfer, and membrane antifouling. In addition, the in situ-introduced surface fluorine species during the formation of F-TiO₂ PHMs provide significant surface fluorination effects, which are not only favorable for the adsorption and activation of reactant molecules, but also beneficial for surface trapping and interfacial transfer of photo-excited electrons and holes. Moreover, the porous hollow superstructures exhibit considerably better compatibility and tolerance to guest modifications, and thus the photocatalytic performances of F-TiO₂ PHMs can be increased by synergetic host and guest modifications, such as ion doping, group functionalization, and nanoparticle loading. The light-harvesting range and intensity can be increased, the charge recombination can be reduced, mass transfer and adsorption can be promoted, and the surface reactivity can be tuned by introducing specific surface functionalities or nanoparticular cocatalysts. Consequently, the entire photocatalytic process can be systematically modulated to optimize the overall photocatalytic performance. The as-prepared F-TiO₂ PHMs typically integrate the merits of interior cavity, hierarchical porosity, and surface fluorination and are open to synergetic host-guest modifications, which provides abundant compositional/structural parameters and specific physicochemical properties for systematically modulating the interconnected photocatalytic processes and promising potential photocatalytic applications.     

Foam-structured Activated Carbon-ceramic as TiO2 Supports for Photocatalytic Degradation of Phenol

An activated foam-structured carbon-ceramic(AFCC) was prepared and investigated as TiO₂ support for the photocatalytic degradation of phenol. AFCC and TiO₂/AFCC catalysts were characterized by N₂ adsorption- desorption and X-ray diffraction(XRD). The effects of AFCC on the photocatalytic activity and the crystallinity of TiO₂ were studied. The results show that the crystallinity and anatase/rutile ratio of TiO₂ loaded on AFCC could be significantly influenced by the calcination temperature. The degradation rate of phenol benefited from the synergistic effects of the adsorption of activated carbon(AC) and the photocatalysis of TiO₂, which suggests that a high surface area of AC is essential to achieve high degradation rates and efficiencies. It was found that the larger mean cell size of AFCC increased the light transmission within the foam.     

Au/TiO2光催化剂的制备及其催化性能

采用改进的等体积浸渍法、光化学沉积法分别制备了不同Au担载量的Au／TiO2光催化剂,以甲基橙的光催化降解反应作为模型反应,考察了金的担载量、预处理条件、制备方法等因素对其光催化性能的影响,以漫反射紫外一可见光谱（DRS）分析了不同金担载量的Au／TiO2光催化剂的光谱特征。结果显示,适当担载量的Au可显著提高TiO2的光催化活性,以改进的等体积浸渍法制备的0．8％Au／TiO2催化剂的光催化活性最高。DRS结果显示,金的担载对TiO2的光谱特征没有影响。     

溶胶-凝胶和浸渍-水热制备方法对TiO_2/AC光催化剂结构和性能的影响

分别采用溶胶-凝胶法和浸渍-水热法制得负载于活性炭(AC)的TiO2催化剂,并用扫描电镜(SEM)、X射线衍射(XRD)、拉曼光谱和氮气吸附等方法对催化剂进行了表征.结果表明:溶胶-凝胶法制得的TiO2以不规则碎片形式涂附在载体表面,而浸渍-水热法制得的球形TiO2颗粒呈柱形生长均匀覆盖在载体表面;不同温度处理的浸渍-水热法制得的TiO2/AC光催化剂的中孔和微孔比表面积均大于溶胶-凝胶法制得的样品,负载的TiO2粒径则小于溶胶-凝胶法制得的样品.对甲基橙(MO)溶液的光催化降解测试结果表明,600℃煅烧为两种方法的最佳热处理温度,浸渍-水热法制得的催化剂光催化效果明显强于溶胶-凝胶法的.     

混晶TiO2光催化剂的制备及机理研究

本文总结了混晶TiO₂光催化剂的各种制备方法,并将其分为两大类：一类是原位生成混晶,如水热法、溶剂热法、溶胶-凝胶法、微乳液-水热联用方法等;另一类是对两种晶型TiO₂材料进行物理混合或对锐钛矿进行高温煅烧,如溶剂混合-煅烧法、高温煅烧法等。其中,后者操作简单易行、对设备要求不高,但获得的混晶TiO₂易产生硬团聚,严重影响其光催化性能;在实际应用中前者制备的TiO₂材料更具优势。同时,本文还对混晶TiO₂光催化机理的研究历程进行了总结,并对其中存在的争议进行了评述。最后,展望了混晶TiO₂光催化剂在环境和能源领域中的应用。