Immobilization of TiO2 nanoparticles on activated carbon fiber and its photodegradation performance for organic pollutants

The immobilization of titanium dioxide(TiO2) on activated carbon fiber(ACF),(TiO2/ACF),was accomplished by sol-gel-adsorption method followed by calcination at temperatures varying from 300 to 600℃ in an argon atmosphere.The material properties were determined by scanning electron microscope(SEM),X-ray diffraction(XRD) and nitrogen adsorption.The photodegradation behavior of TiO2/ACF was investigated in aqueous solutions using phenol and methyl orange(MO) as target pollutants.The effects of calcination temperature,photocatalyst dosage,initial solution pH and radiation time on the degradation of organic pollutants were studied.It was found that organic pollutants could be removed rapidly from water by the TiO2/ACF photocatalyst and the sample calcined at 500℃ exhibited the highest removal efficiency.Kinetics analysis showed that the photocatalytic degradation reaction can be described by a first-order rate equation.In addition,the possibility of cyclic usage of the photocatalyst was also confirmed.Moreover,TiO2 is tightly bound to ACF and can be easily handled and recovered from water.It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.     

Liquid phase heterogeneous photocatalytic ozonation of phenol in liquid-solid fluidized bed: Simplified kinetic modeling

The isotherms of original AC (activated carbon) and photocatalysts (TiO2-AC) calcined at 500℃ for phenol were measured. The results showed a reversible adsorption of phenol onto both kinds of particles at 25℃, and could be fitted well to the Freundlich adsorption equation for the dilute solution. Five oxidation processes, namely O3 , O3 /UV, O3 /UV/AC, O2 /UV/TiO2 and O3 /UV/TiO2 , for phenol degradation in fluidized bed were evaluated and compared, and the photocatalytic ozonation was found to give the hig...     

TiO2-loaded activated carbon fiber: Hydrothermal synthesis,adsorption properties and photo catalytic activity under visible light irradiation

TiO₂-loaded activated carbon fibers (ACF) were prepared by a hydrothermal method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry and UV–vis diffuse reflectance spectra (DRS). SEM images showed that the TiO₂ nanoparticles were deposited on the surface of ACF, and the particle size and loading amount of TiO₂ were varied by changing the initial concentration of tetrabutyl titanate (TBOT). The results of an ash experiment showed that the loading amounts of TiO₂ were 18.4%, 43.3%, 52.5%, 75.1%, and 91.1% for initial concentrations of TBOT of 0.07, 014, 0.21, 0.28, and 0.35 mol/L, respectively. Physical interactions played an important role in the formation of TiO₂/ACF composite fibers that absorb UV and visible light. Compared with those of ACF, improved adsorption and photocatalytic activity toward Rhodamine B (RhB) were observed for TiO₂/ACF composite fiber. The Rhodamine B could be removed efficiently by TiO₂/ACF composite fibers, and the TiO₂ loading amount had a significant effect on the photocatalytic activity of TiO₂/ACF composite fibers.     

Optimized synthesis and photovoltaic performance of TiO2 nanoparticles for dye-sensitized solar cell

This paper presents response surface methodology （RSM） as an efficient approach for modeling and optimizing TiO2 nanoparticles preparation via co-precipitation for dye-sensitized solar cell （DSSC） perfor- mance. Titanium （IV） bis-（acetylacetonate） di-isopropoxide （DIPBAT）, isopropanol and water were used as precursor, solvent and co-solvent, respectively. Molar ratio of water, aging temperature and calcina- tion temperature as preparation factors with main and interaction effects on particle characteristics and performances were investigated, Particle characteristics in terms of primary and secondary sizes, crys- tal orientation and morphology were determined by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Band gap energy and power conversion efficiency of DSSCs were used for perfor- mance studies. According to analysis of variance （ANOVA） in response surface methodology （RSM）, all three independent parameters were statistically significant and the final model was accurate. The model predicted maximum power conversion efficiency （0.14%） under the optimal condition of molar ratio of DIPBAT-to-isopropanol-to-water of 1 ： 10：500, aging temperature of 36 C and calcination temperature of 400 ℃. A second set of data was adopted to validate the model at optimal conditions and was found to be 0.14 ± 0.015%, which was very close to the predicted value. This study proves the reliability of the model in identi（ving the optimal condition for maximum performance.     

碳纳米管纤维及其传感器力电性能实验研究

基于UTM T150微纳米力学测试系统搭建了纤维力电耦合测试平台,并对碳纳米管纤维进行了多组力电耦合作用下的拉伸性能实验研究。通过观察分析碳纳米管纤维的电阻-应变曲线,发现其电阻变化与应变大小密切相关,随着应变的不断变大,碳纳米管纤维的电阻也在逐渐增加。基于此,设计制作了碳纳米管纤维柔性应变传感器,并将其贴在标准试件上分别进行了弯曲变形测试、单次/循环加载性能测试以及标定实验。结果表明:当对试件进行加载时,碳纳米管纤维柔性应变传感器的电阻会随着载荷的增大而增大;当载荷逐渐消失时,其电阻会逐渐减小直至回归初始电阻值附近。这表明碳纳米管纤维具备优异的电学与力学特性,并且利用它所制作的柔性应变传感器也有着较好的灵敏度与稳定性。     

碳纤维/环氧树脂仿贝壳珍珠层结构强韧机制与性能优化的实验研究

材料的轻量化设计在生产实践中具有重大意义,将天然贝壳珍珠层结构应用到现有的高性能人工合成材料上,能够获得性能更加优异的轻质高强结构材料。本文采用碳纤维/环氧树脂复合材料,设计出了多种具有规则砖-泥交错叠层结构的仿贝壳珍珠层复合材料,通过力学性能测试实验、微观结构表征及力学原理分析等对不同片层单元长度及不同单元搭接形式的材料在拉伸载荷下的力学行为进行了研究,探索了其微观结构对材料强度和韧性的影响机制。结果表明,砖-泥交错叠层结构中砖块单元长度是影响材料强度和韧性的关键因素,而在此基础上通过对片层搭接形式的优化设计,可进一步改善其内部的应力分布与载荷传递机制,从而实现其强度和韧性的进一步提升与有效调控。     

宏微观渐进展开损伤本构模型及其在碳纤维增强复合材料中的应用

基体开裂、纤维拔出、界面剥离等是碳纤维增强复合材料常出现的局部各向异性损伤现象,这些损伤逐渐扩展,削弱了材料的强度和刚度,影响材料的承载能力.对此利用宏微观摄动理论对位移进行双范围渐进展开,在微观位移中引入损伤应变,通过计算损伤应变集中因子,得到了含损伤的均质化损伤弹性常数(宏观有效刚度矩阵),用平均法和混合法检验了无...