陶瓷表面 TiO2薄膜的制备及光催化性能研究

采用化学溶胶-凝胶法制备TiO2溶胶，用浸渍-提拉方式在陶瓷表面制成锐钛矿相TiO2薄膜。用X射线衍射法(XRD)确定了晶型及晶粒的大小；用光电子能谱测定了其微观成分及其含量；考察了7种过渡金属离子掺杂后对甲基橙降解的光催化性能的影响及其变化规律，并对陶瓷和玻璃的光催化活性进行了比较。实验结果表明：掺杂Mn及Ni离子对于提高TiO2薄膜的光催化活性有明显的促进作用，降解30min后，降解率分别达到79．7％，80.8％。瓷片和玻璃的光催化活性要视掺杂的金属离子而定，不同的掺杂离子对瓷片和玻璃的光催化活性有不同的作用效果。     

纳米TiO2光催化剂的结构调控及其光催化活性研究

以酞酸丁酯和冰醋酸分别为前驱物和酸催化剂,采用溶胶 凝胶法制备了纳米 TiO2 粉体, 并且通过改变水体溶液中酞酸丁酯,醋酸和水的摩尔比来调控纳米TiO2 粉体的大小以及光催化活性;探讨在溶胶 凝胶法制备过程中在水溶液中添加表面活性剂十二烷基苯磺酸钠 ( DBS ) 和共溶剂无水乙醇(CH3CH2OH)来调控TiO2 粉体以及光催化活性。用X射线衍射和透射电子显微镜等手段对不同条件制备的纳米粉体的微观结构进行了表征,并且以甲基橙染料的降解为模型反应,考察了不同制备条件下的催化剂的光催化活性,而且对纳米粉体结构和光催化性能之间的关系进行了讨论。     

铁掺杂TiO2光催化剂的制备及光催化性能

采用溶胶-凝胶法制备铁掺杂纳米TiO2光催化剂。通过XRD、FT-IR、UV-Vis、PL等对Fe-TiO2样品进行表征和分析,并以亚甲基蓝（MB）作为目标降解物,考察经不同热处理温度及不同掺铁量Fe-TiO2样品对MB的降解效果。结果表明所制备的Fe-TiO2样品的晶型为锐钛矿相与金红石相的混晶相,铁掺杂抑制了晶粒的生长和晶型的转变,样品的吸收阈值波长向可见光红移约68nm,提高了TiO2的光催化活性。在普通日光灯下,经500℃热处理、掺铁量与TiO2摩尔比为1∶200条件下制备的催化剂其光催化活性明显高于Degussa P25。     

纳米TiO2的制备及其光催化活性

用高分子凝胶法制备纳米TiO2,研究了烧结温度对晶粒大小的影响以及粉体的平均粒径和光催化活性的关系.结果表明:高分子凝胶形成的小且均匀的网格限制了TiO2晶粒之间的接触和团聚,因此在较低温度下即可合成分散性好、平均粒径细小、粒径均匀且无团聚具有锐钛矿结构的纳米TiO2.随着煅烧温度的升高,纳米TiO2的平均粒径逐渐增大.纳米TiO2平均粒径的减小可提高其光催化活性以及对次甲基蓝的降解速率.适量的TiO2可以使次甲基蓝的降解率达到70%.     

TiO2纳米管的制备及光催化性能研究

以氟化铵水溶液为电解质,采用阳极氧化法,在钛片基体上制备出TiO2纳米管阵列.用FESEM、XRD等测试方法对样品进行表征,采用UV-1800型紫外-可见分光光度计检测TiO2纳米管对甲基橙的光催化性能.结果表明,氧化电压为50V,氧化时间为10h,煅烧温度为500℃时得到的TiO2纳米管对甲基橙的降解效果最好.     

铁氮共掺杂TiO2光催化剂的制备及光催化性能

采用溶胶-凝胶法与微波合成法相结合制备铁氮共掺杂的TiO2光催化剂。通过XRD、FT-IR、UV-Vis、PL等对Fe-N-TiO2样品进行表征和分析,并以亚甲基蓝（MB）作为目标降解物,考察经不同温度热处理及不同掺铁量的样品对MB的降解效果。结果表明所制备的样品在700℃热处理5h后为锐钛矿相与金红石相混晶,样品的吸收阈值波长向可见光红移约45nm。铁氮共掺杂抑制了样品从锐钛矿相向金红石相的转变,提高了TiO2的光催化活性。在普通日光灯下,热处理温度为600℃、掺铁量与TiO2摩尔比为1︰200条件下制备的样品,其光催化活性明显高于Degussa P25。     

液相沉积法制备纳米TiO2薄膜及其光催化活性研究

采用液相沉积法,在ITO玻璃上直接沉积出具有光催化活性的纳米TiO2薄膜。用XRD、AFM、UV—Vis对TiO2薄膜的物相、形貌、透明性和厚度等进行表征,并研究了TiF6^2-水溶液的浓度、反应物TiF6^2-和H3BO3的摩尔比、沉积时间等对沉积TiO2薄膜的结构和性能的影响。此外,还用亚甲基蓝的降解评价了TiO2薄膜的光催化活性。     

多孔TiO2的制备表征及光催化研究

以钛酸四丁酯为前驱物，在溶胶-凝胶法和硬脂酸法的合成样品的过程中添加正硅酸乙酯，分别合成出纳米TiO2，焙烧成晶后通过HF除去硅，形成了多孔TiO2。通过XRD、SEM、UV-Vis、BET等测试手段，比较正硅酸乙酯对不同合成方法合成的样品的影响。在对甲基橙的紫外光催化试验中，添加正硅酸乙酯再由HF处理后合成的样品表现出较高的催化活性，这与此方法合成的样品的表面积较大有关。     

TiO2/MXene纳米复合材料的可控制备及在光催化和电化学中的应用研究进展

TiO2纳米材料因其存在高的光生电子-空穴对复合速率、电子迁移率低、导电性差以及可逆容量低等问题,使其在光催化和电化学等领域的应用受到限制.MXene(Mn+1 Xn Tx)作为一种新型的二维过渡金属碳化物、氮化物或碳氮化物,具有独特的二维层状结构、良好的金属导电性和较高的载流子迁移率等特性,将其引入TiO2纳米材料中构建TiO2/MXene纳米复合材料,利用两者的协同作用可进一步提高光电性能.本文从TiO2纳米材料的角度出发,系统综述了零维、一维和二维TiO2与MXene纳米复合材料的可控制备、结构性能及在光催化和电化学领域应用的最新研究进展,并着重介绍了纳米复合材料的构筑机理及MXene对提高TiO2的光催化和电化学性能的增强机制等,分析了目前TiO2/MXene复合材料的制备及其在光催化和电化学领域应用中存在的不足.此外,从优化制备工艺、提升性能和探索相应的性能增强机制等方面对未来TiO2/MXene复合材料的研究方向进行了展望.     

纳米TiO2薄膜的制备及其光催化性能研究

采用溶胶-凝胶(Sol-gel)法在玻璃衬底上制备了纳米TiO2薄膜.采用X射线衍射仪(XRD)、紫外可见一光谱(UV/vis)和原子力显微镜(AFM)对纳米TiO2进行表征.结果表明,经300～700℃退火得到的TiO2粉体呈锐钛矿相,经800℃退火得到了锐钛矿相与金红石相的混合晶相,经900℃退火完全转化为金红石相.薄膜表面粒子分布均匀,表面平均粗糙度为1.54nm,该薄膜具有较高的光催化活性,可直接用于光催化降解有机物等领域,具有广阔的应用前景.     

Pt/Fe_2O_3/TiO_2的制备、表征及其光催化活性研究

报道了担载不同贵金属或过渡金属氧化物的TiO2 催化剂对空气中微量甲醛的光催化氧化的研究结果。实验发现 ,TiO2 上担载Fe2 O3 或Pt时对甲醛均有较高的光催化氧化活性。同时担载双组分的光催化剂Pt Fe2 O3 TiO2 ,由于 2种组分的协同作用 ,具有更高的光催化活性。研究了催化剂制备因素、催化剂的结构及表面特性对催化活性的影响     

Responding Depth of Photocatalytic Activity of TiO2 Self-assembled Films

The electrostatically self-assembly method is getting strategically important to prepare multilayer thin films. With careful choice of component materials, this method should allow for the preparation of multilayer thin films with a variety of excellent technological properties. Ti02/PSS multilayer thin films with ordered structure were prepared by electrostatic self-assembly method. UV-Vis-NIR spectrophotometer, X-ray photoelectron spectroscopy (XPS), and atom force microscopy (AFM) were used to characterize the structure and performance of the multilayer films. Because electrostatically self-assembly method allows molecular-level control over the film composition and thickness, this paper studied the responding depth of photocatalytic activity of Ti02 self-assembled films in detail.     

Photocatalytic decomposition of 2-chlorophenol in aqueous solution by UV/TiO2 process with applied external bias voltage

The decomposition of 2-chlorophenol by UV/TiO2 process with the application of external bias voltage was examined in this study. Experiments were conducted in a batch reactor using TiO2-coated titanium sheet as anode and platinum sheet as cathode. The anode photocatalysis of 2-chlorophenol was totally inhibited for experiments conducted with the application of external anodic bias voltage lower than the flat band potential of TiO2. The decomposition rate of 2-chlorophenol was then increased with increasing external anodic bias voltage applied up to 0.0 V (versus SCE). The application of external bias voltage higher than 1.0 V did not markedly promote the photocatalysis of 2-chlorophenol possibly because the photocurrent induced was constant. Experimental results indicated that the decomposition of 2-chlorophenol was more effective for experiments conducted in acidic solutions due to the lower flat band potential of TiO2 and the higher photocurrent induced. The presence of electron scavengers in aqueous solution, such as oxygen molecules, may increase the decomposition rate of 2-chlorophenol. However, the effect of dissolved oxygen was diminished for experiments conducted with applied external bias voltage. The photocatalytic decomposition rate of 2-chlorophenol was enhanced linearly with the increasing UV light intensity when the external bias voltage was applied.     

Photocatalytic Activities of TiO2 Coated on Different Semiconductive SiC Foam Supports

Different semiconductive SiC foam supports were prepared by varying the sintering temperature and atmosphere, and with or without alkaline solution treatment and high temperature oxidation following a macromolecule pyrogenation combined with reaction bonding method. Nano-TiO2 particles were immobilized onto these SiC foam supports by a composite sol-gel method. The phase, surface morphology, the type of conduction and the photocatalytic activity of the TiO2-SiC composite photocatalysts were studied. The TiO2 coated on p-type Si-free SiC support showed the highest photocatalytic efficiency in degradation of 4- aminobenzenesulfonic acid （4-ABS） in aqueous solution as compared to that coated on n-type SiC support and p-type SiC supports with residual Si or Si02 on the surface. The result showed that the TiO2 coatings immobilized on p-type semiconductive SiC foam supports exhibited obviously higher photocatalytic activity in comparison to that coated on n-type SiC foam support. The p-n heterojunctions formed between the p-type SiC supports and n-type TiO2 coatings might be able to account for the better charge separation and transfer as well as the photocatalytic activity of the TiO2-SiC composite photocatalyst.     

Photocatalytic activity of manganese, chromium and cobalt-doped anatase titanium dioxide nanoporous electrodes produced by re-anodization method

Transition metal-doped TiO₂ electrodes were prepared by re-anodization and characterized. The structure of these electrodes was investigated by X-ray diffraction and electron diffraction, which mainly showed typical characteristic anatase reflections without any dopant-related peaks. The amount of transition metal dopant in TiO₂ was kept at approximately 1.0 at.%, as measured by energy dispersive X-ray spectroscopy. The effects of different types of dopants on the photocatalytic activity were revealed by measuring the degradation of an organic aqueous solution containing a dye (acid red G) using a combination of ultraviolet (UV) light energy in the presence of these electrodes. The photocatalytic efficiency was remarkably enhanced by the incorporation of Mn ²⁺ and Cr³⁺. Mn²⁺ showed the most significant enhancement. However, Co²⁺ accelerated the rate of acid red G degradation only slightly. Langmuir-Hinshelwood rate expression was employed for the degradation of acid red G by UV/TiO₂ electrodes system. The adsorption equilibrium constant, the rate constant, and the initial degradation rate were determined for different electrodes. The effect of the concentration of Mn²⁺ on the degradation of acid red G was also investigated and the results showed that there is an optimal value (about 1.0 at.%) of the concentration of Mn²⁺ for inducing faster degradation of the dye. The enhanced photocatalytic degradation rate of acid red G in the presence of transition metals is attributed to the increase of the charge separation in these systems.     

掺杂TiO2纳米膜光催化性能的研究进展

针对TiO2在实现清洁能源和净化环境方面的应用及其局限性,对各种类型掺杂TiO2薄膜的光催化性能进行了大量的研究.根据国内外近期在此领域的研究现状,综述了掺杂各种金属离子、非金属离子对TiO2薄膜的光催化活性机理的影响.掺杂主要是通过影响薄膜的晶相组成、能级、可见光响应范围等来改善光催化性能.对于TiO2薄膜,涂膜基体、热处理的制度和气氛等也有重要的影响.     

Photocatalytic activity studies of TiO2 thin films prepared by r.f. magnetron reactive sputtering

A series of transparent titanium dioxide thin films have been obtained on microscope glass slides by means of r.f. magnetron reactive sputtering using Ar and O₂ mixed gases. The photocatalytic activity of the TiO₂ thin films was evaluated by the degradation of rhodamine B dye wastewater. The influences of substrate temperatures and total sputtering pressures on the photocatalytic activity of the TiO₂ films were investigated. It was observed that substrate temperature had little influences on the photocatalytic activity, but the photocatalytic activity of the TiO₂ thin films was improved by decreasing the total sputtering pressure.     

纳米TiO2光催化氧化灭菌的研究进展

概述了二氧化钛光催化氧化灭菌的最新研究进展,讨论了其灭菌机理,TiO2光催化产生的活性成分(·OH、·O2、HO2·、H2O2)攻击细菌的细胞壁、细胞膜及内部成分,使细菌功能单元失活而导致细菌死亡;综合分析了影响氧化灭菌的各种因素,并展望了今后的研究.     

Photocatalytic and electrochemical combined treatment of textile wash water

Various chemical and physical processes for treatment of textile effluent are not destructive but they only transfer the contaminants from one form to another. The presence of high concentration of organic dye and total dissolved solids (TDS) in the effluent that are not removed by biological treatment must be eliminated by an alternative method to the conventional ones is the advanced oxidation process (AOP). A procion blue dye effluent was treated by photo and electrochemical oxidation process as well as by combining photocatalytic degradation using TiO2 suspensions. Chemical oxygen demand (COD) and colour removal can be used to follow the degradation of the organic pollutant. The effects of pH, current density, flow rate of effluent that passes into the reactor and supporting electrolyte were studied. Comparative studies were carried out on photocatalytic and electrochemical process to degrade the procion blue. The maximum COD reduction and colour removal were 96 and 100%, respectively. Photodegradation efficiency of dye was high when photolysis was carried out in the presence of 40 mg/l of TiO2.     

掺铁二氧化钛薄膜的自组装制备和光催化性能研究

以TiCl4为钛源,SAMs为模板,Fe（NO3）3·9H2O为铁源,采用自组装方法于低温液相反应体系中分别成功地制备出大面积二维结构纳米的纯净和掺铁Ⅱ0：薄膜,通过拉曼光谱、高分辨透射电镜、荧光发射光谱等方法对样品进行表征,研究紫外光和可见光下纳米薄膜对甲基橙溶液的光催化降解过程以及紫外光下对甲苯的降解效率,探讨了掺铁后对TiO2：的光催化活性的影响,结果表明,此方法不需要高温煅烧即可得到高催化活性的以金红石为主的掺铁二氧化钛纳米薄膜。