Sonocatalytic Damage of Bovine Serum Albumin (BSA) in the Presence of Nanometer Titanium Dioxide (TiO_2) Catalyst

The sonocatalytic damage of bovine serum albumin （BSA） was studied in the presence of nanometer titanium dioxide （TiO2） powders by low frequency （80 kHz） ultrasound. The destruction of secondary structure and change of α-helical structure of BSA were reflected by ultraviolet （UV） and circular dichroism （CD） spectroscopies.

Fabrication of Dye Sensitized Solar Cell Based on Titanium Dioxide (TiO₂)

The Dye Sensitized Solar Cell (DSSC) plays an important role because of low material cost, ease of production and high conversion efficiency as compared to other thin-film solar cell technologies. The main objective is to create and find the best configuration of the solar cell based on materials that are inexpensive and highly efficient in solar energy conversion and subsequently test the efficiency of dye sensitized titanium dioxide solar cell. We begin the process with two glass plates coated with Fluorine tin oxide (FTO). Titanium dioxide is applied to the conductive side of one plate and the other plate is coated with graphite. A dye is adsorbed on to the TiO2 layer and then the plates are sandwiched together. A drop of iodide electrolyte is then added between the plates. The tests carried out indoors under a lamp emitting all wavelengths in the visible spectrum were not found to provide consistent data due to substantial heating of the cell. The outdoor tests carried out in natural sunlight exhibited steady voltage at much higher level. Future research will involve the incorporation of quantum dots instead of the organic dye as a sensitizer. Quantum dots have the advantages of providing tunable band gaps and the ability to absorb specific wavelength.

A Review of the Production Cycle of Titanium Dioxide Pigment

Titanium is a very important element for several industrial applications, being one of the ninth most abundant elements in the Earth’s crust (0.63% wt). In this work it will discuss the different mining and industrial activities involved in the production of titanium dioxide. The first step analyzed will treat about the beneficiation mining process of titanium mineral, and secondly, it will discuss the two main processes of the TiO2 manufacturing (sulphate and chloride routes). In addition, we will show different uses of the titanium dioxide pigment as filler in paper, plastics and rubber industries and as flux in glass manufacture, etc. Finally, we will show that the old wastes are currently called co-products since they were valorized, being commercialized by the Spanish industry of TiO2 production in different fields such as agriculture, civil engineering, or cement manufacturing.

活性炭载体对TiO_2/AC光催化降解苯酚影响研究

分别以典型煤基活性炭和椰壳活性炭为载体,采用溶胶-凝胶法制备了TiO2/AC复合光催化剂,采用低温氮气吸附、X射线衍射、扫描电镜等对其性能进行了表征,分析了活性炭载体对复合光催化剂性能的影响。结果表明:TiO2在椰壳活性炭载体上的负载率高于煤基活性炭,TiO2负载使椰壳活性炭的比表面积和微孔容明显减小,TiO2溶胶对微孔的堵塞作用显著,煤基复合光催化剂对苯酚的吸附和光催化效果优于椰壳复合光催化剂。

TiO_2纳米棒阵列光电化学性能的综合实验设计

运用水热合成路线制备出一种准直有序的TiO_2纳米棒阵列材料,采用XRD、SEM等手段对材料的形貌、结构进行表征,重点考察了TiCl_4预处理对TiO_2阵列光电化学性能的影响。结果表明,TiO_2纳米棒直径约150 nm,长度在2～3μm,整齐有序排列,其中经过60 mmol/L TiCl_4预处理的样品具有最佳的光电流密度。电化学阻抗谱结果表明,该样品的电极/电解液界面电荷转移电阻最小,这与该条件下得到的TiO_2纳米阵列的结晶质量增强有关。本实验原料廉价、操作简单,且涵盖多个知识点,不仅有利于培养本科生收集、整理、分析实验数据的技能,还可以培养他们发现问题和解决问题的综合创新能力。

水热法制备TiO_2薄膜光催化降解性能的研究

以 Ti( SO4) 2 水溶液为前驱物 ,尿素为沉淀剂 ,采用水热法制备了锐钛矿型 Ti O2 薄膜 ,研究了该薄膜光降解苯甲酸的性能以及 Ti O2

Time-resolved photoluminescence of anatase/rutile TiO_2 phase junction revealing charge separation dynamics

Junctions are an important structure that allows charge separation in solar cells and photocatalysts. Here, we studied the charge transfer at an anatase/rutile TiO2 phase junction using time-resolved photoluminescence spectroscopy. Visible （-S00 nm） and near-infrared （NIR, -830 nm） emissions were monitored to give insight into the photoinduced charges of anatase and rutile in the junction, respectively, New fast photoluminescence decay components appeared in the visible emission of futile-phase dominated TiO2 and in the NIR emission of many mixed phase TiO2samples. The fast decays confirmed that the charge separation occurred at the phase junction. The visible emission intensity from the mixed phase TiO2 increased, revealing that charge transfer from rutile to anatase was the main pathway. The charge separation slowed the microsecond time scale photolumines- cence decay rate for charge carriers in both anatase and rutile. However, the millisecond decay of the charge carriers in anatase TiO2 was accelerated, while there was almost no change in the charge carrier dynamics of rutile TiO2. Thus, charge separation at the anatase/rutile phase junction caused an increase in the charge carrier concentration on a microsecond time scale, because of slower electron-hole recombination. The enhanced photocatalytic activity previously observed at ana- tase/rutile phase junctions is likely caused by the improved charge carrier dynamics we report here. These findings may contribute to the development of improved photocatalytic materials.

TiO_2光催化性能及在水处理中的应用

文章介绍了TiO2 光催化的机理,分析了催化剂、光源、有机物浓度等因素对光催化效率的影响。

多孔TiO_2陶瓷光催化剂降解糠醛废水

以钛酸四丁酯等为原料 ,采用简单工艺制得多孔TiO2 陶瓷光催化剂 ;并研究了利用多孔TiO2 陶瓷光催化降解糠醛废水。结果表明 ,在紫外灯下照射 6 0min ,糠醛废水的COD去除率可达 5 9.8% ,而通入空气有利于污染物的去除。

高强紫外线辐照对TiO2改性涤纶纤维结构和力学性能的影响

为探究高强度紫外线对涤纶造成光损伤的原因及TiO 2涂层对涤纶的防护机理,文章采用水热法在涤纶纤维表面沉积纳米TiO 2颗粒,以化学镀银涤纶纤维作为比较,借助扫描电子显微镜、红外光谱和X射线衍射技术对纤维表面形貌、分子结构、结晶和取向结构进行了研究,测定高强度紫外线辐照下的纤维力学拉伸性能。结果表明:高强度紫外线辐照短时间内就会引起涤纶和化学镀银涤纶纤维的表观晶粒尺寸增大,结晶指数减小,从而导致力学性能下降,而负载锐钛矿型纳米TiO 2的涤纶纤维抵抗高强度紫外线辐照时间会显著延长。

Highly efficient Cu/anatase TiO2 {001}-nanosheets catalysts for methanol synthesis from CO2

Anatase TiO2 nanosheets（-ns-） with dominant exposed {001} facets were used as support to load copper,and the synthesized Cu/TiO2-ns catalysts were evaluated for CO2 hydrogenation to methanol. Under the reaction conditions, P = 3.0 MPa, T = 260 ℃, V（N2）：V（H2）：V（CO2） = 8：69：23 and gas hourly space velocity（GHSV） = 3600 mL g-1h-1, the methanol yield reached an appealing high value, 5.6%. Copper-loading amount, calcination temperature and reduction atmosphere have been investigated in this work, which significantly influence the particle sizes of copper and/or the defect concentration in TiO2, then leading to different catalytic performance. Characterizations of XRD, EPR, CO2-TPD and FTIR demonstrate that higher specific surface area of Cu is good for the hydrogenation of CO2 and adequate amount of Ti3＋ plays important roles in CO2 activation. Both of them facilitate high turnover frequency（TOF） of methanol formation.

Research progress of TiO2 photocathodic protection to metals in marine environment

Corrosion protection has become an important issue as the amount of infrastructure construction in marine environment increased.Photocathodic protection is a promising method to reduce the corrosion of metals,and titanium dioxide(TiO2) is the most widely used photoanode.This review summarizes the progress in TiO2 photo gene rated protection in recent years.Different types of semiconductors,including sulfides,metals,metal oxide s,polymers,and other materials,are used to design and modify TiO2.The strategy to dramatically improve the efficiency of photoactivity is proposed,and the mechanism is investigated in detail.Characterization methods are also introduced,including morphology testing,light absorption,photoelectrochemistry,and protected metal observation.This review aims to provide a comprehensive overview of Ti02 development and guide photocathodic protection.

Systematic study of H2 production from catalytic photoreforming of cellulose over Pt catalysts supported on TiO2

Hydrogen(H2)production from photocatalytic reforming of cellulose is a promising way for sustainable H2 to be generated.Herein,we report a systematic study of the photocatalytic reforming of cellulose over Pt/m-TiO2(i.e.mixed TiO2,80%of anatase and 20%of rutile)catalysts in water.The optimum operation condition was established by studying the effect of Pt loading,catalyst concentration,cellulose concentration and reaction temperature on the gas production rate of H2(r(H2))and CO2(r(CO2)),suggesting an optimum operation condition at 40°C with 1.0 g·L^-1of cellulose and 0.75 g·L^-1of 0.16-Pt/m-TiO2 catalyst(with 0.16 wt%Pt loadting)to achieve a relatively sound photocatalytic performance with rH2=9.95μmol·h^-1.It is also shown that although the photoreforming of cellulose was operated at a relatively mild condition(i.e.with an UV-A lamp irradiation at40°C in the aqueous system),a low loading of Pt at^0.16 wt%on m-TiO2 could promote the H2 production effectively.Additionally,by comparing the reaction order expressed from both r(H2)(a1)and r(CO2)(a2)with respect to cellulose and water,the possible mechanism of H2 production was proposed.

二氧化钛（TiO2）/氧化石墨烯复合催化氧化垃圾渗滤液

本文通过比较二氧化钛(TiO2)、氧化石墨烯和TiO2/氧化石墨烯复合等3种催化剂处理垃圾渗滤液的效果,分析了它们的效果与投加量、反应时间之间的关系.试验结果表明,当投加TiO2/氧化石墨烯复合催化剂与渗滤液COD质量比为0.7、反应时间为2h时,处理条件最佳、催化剂对渗滤液COD的去除率为92.57%,处理后的渗滤液氨氮浓度为2016mg/L,可生化性BOD5/COD为0.83.综上,在这3种催化剂中TiO2/氧化石墨烯复合催化剂处理垃圾渗滤液的效果最好.

Synthesis of TiO_2/g-C_3N_4 nanocomposites with phosphate–oxygen functional bridges for improved photocatalytic activity

One of the most general methods to enhance the separation of photogenerated carriers for g‐C3N4is to construct a suitable heterojunctional composite,according to the principle of matching energy levels.The interface contact in the fabricated nanocomposite greatly influences the charge transfer and separation so as to determine the final photocatalytic activities.However,the role of interface contact is often neglected,and is rarely reported to date.Hence,it is possible to further enhance the photocatalytic activity of g‐C3N4‐based nanocomposite by improving the interfacial connection.Herein,phosphate-oxygen(P-O)bridged TiO2/g‐C3N4nanocomposites were successfully synthesized using a simple wet chemical method,and the effects of the P-O functional bridges on the photogenerated charge separation and photocatalytic activity for pollutant degradation and CO2reduction were investigated.The photocatalytic activity of g‐C3N4was greatly improved upon coupling with an appropriate amount of nanocrystalline TiO2,especially with P-O bridged TiO2.Atmosphere‐controlled steady‐state surface photovoltage spectroscopy and photoluminescence spectroscopy analyses revealed clearly the enhancement of photogenerated charge separation of g‐C3N4upon coupling with the P-O bridged TiO2,resulting from the built P-O bridges between TiO2and g‐C3N4so as to promote effective transfer of excited electrons from g‐C3N4to TiO2.This enhancement was responsible for the improved photoactivity of the P-O bridged TiO2/g‐C3N4nanocomposite,which exhibited three‐time photocatalytic activity enhancement for2,4‐dichlorophenol degradation and CO2reduction compared with bare g‐C3N4.Furthermore,radical‐trapping experiments revealed that the·OH species formed as hole‐modulated direct intermediates dominated the photocatalytic degradation of2,4‐dichlorophenol.This work provides a feasible strategy for the design and synthesis of high‐performance g‐C3N4‐based nanocomposite photocatalysts for pollutant degradation and CO2reduction.

分级多孔结构Bi2WO6/TiO2纳米材料的生物模板法制备及其光催化性能

本文以玉米秸秆为生物模板,高温焙烧制备了具有玉米秸秆分级多孔结构的纯相二氧化钛(TiO2),再通过水热法制备了钨酸铋(Bi2WO6)/二氧化钛(TiO2)复合催化材料.运用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)及紫外可见(UV-vis)漫反射等手段对催化材料的组成和微观结构进行了表征分析.结果表明,通过高温焙烧法制备的样品为纯相锐钛矿型TiO2,TiO2表面呈片状结构,通过多孔道相互联结形成多孔蜂窝结构,Bi2WO6呈花球状附着在TiO2表面,形成Bi2WO6/TiO2复合材料.以氙灯为光源,采用罗丹明B作为光催化降解污染物评价复合催化材料的光催化性能.结果表明:相较于纯相TiO2材料,Bi2WO6/TiO2复合材料在可见光下表现出对罗丹明B较好的催化活性.在氙灯光照射120min后,采用模板法制备的Bi2WO6/TiO2对罗丹明B的降解率高于无模板制备的Bi2WO6/TiO2复合材料,分别为99.3%和81.7%.在Bi2WO6/TiO2掺杂比为1∶2时,复合光催化材料表现出的光催化活性最好,并且在溶液pH=6、复合光催化材料投加量为0.4g时降解效果最佳.复合催化剂的光催化活性的提高主要由于Bi2WO6和TiO2形成了异质结构,提高了光生电子-空穴对的分离效率.

Thermal and Structural Analyses of PMMA/TiO₂Nanoparticles Composites

In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.

Computational Study on Interactions between CO2 and （TiO2）n Clusters at Specific Sites

The energetic pathways of adsorption and activation of carbon dioxide (CO2) on low-lying compact (TiO2)n clusters are systematically investigated by using electronic structure calculations based on density-functional theory (DFT). Our calculated results show that CO2 is adsorbed preferably on the bridge O atom of the clusters, forming a "chemisorption" carbonate complex, while the CO is adsorbed preferably to the Ti atom of terminal Ti-O.The computed carbonate vibrational frequency values are in good agreement with the results obtained experimentally, which suggests that CO2 in the complex is distorted slightly from its undeviating linear configuration. In addition, the analyses of electronic parameters, electronic density, ionization potential, HOMO-LUMO gap, and density of states(DOS) confirm the charge transfer and interaction between CO2 and the cluster. From the predicted energy profiles, CO2 can be easily adsorbed and activated, while the activation of CO2 on (TiO2)n clusters are structure-dependent and energetically more favorable than that on the bulk TiO2. Overall, this study critically highlights how the small (TiO2)n clusters can influence the CO2 adsorption and activation which are the critical steps for CO2 reduction the surface of a catalyst and subsequent conversion into industrially relevant chemicals and fuels.

Analysis and characterization of microstructures of a TiO_2/bamboo charcoal composite and modified poplar veneer

A type of TiO/bamboo charcoal composite made by a dip-dry method was loaded onto wood veneer with a vacuum- pressure method in order to prepare modified poplar veneer. The pore structure parameters and surface morphology of the TiO2/ bamboo charcoal composite were determined and analyzed by means of a porosimetry analyzer and SEM. The results show that the surface morphology of the composite does not change after being loaded with nano TiO2. However, its specific surface area （359.814 m^2·g^-1）, pore volume （0.317 cm^3.g^-1） and average pore diameter （3.526 nm） increased; particularly the cumulative volume of pores was increased by 65.83%. In addition, the distribution range of the pores was wider than that of the bamboo charcoal. Combining the SEM of unmodified and modified poplar veneer, the results of X-ray photoelectron spectroscopy revealed that actually some TiOz compounds, i.e., 4.08%, are imbedded in the modified poplar veneer.

One-pot Synthesis of TiO2 Nanoparticles in Suspensions for Quantification of Titanium Debris Release in Biological Liquids

In this work we have developed an analytical method to measure potential titanium debris released from TiO2 nanotube layers devices immersed in biological fluids. This quantitative study is highly required to ensure both the security and non toxicity of the nanostructured surfaces used as future implantable medical devices in the living. A one-pot synthesis process is developed to produce high quality standard solutions of titanium dioxide nanoparticles in aqueous medium. The elaborated dispersion is then used to fabricate standard solutions in both aqueous and human blood plasma media. The synthesized nanoparticles dispersion was characterized by granulometry. The nanoparticles structure and morphology were then observed using Transmission Electron Microscopy (TEM). Thermogravimetric Analysis (TGA) was used to evaluate the concentration of TiO2 in the suspension. A quantitative routine by the use of Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) is developed. The quantification threshold of titanium species is found to be in the 30 - 40 ppb range. None interference is detected between the particles and the human blood plasma. Using the established quantitative routine, the titanium species release from titania nanotube layers in human blood plasma is evaluated.