二氧化钛光催化氧化亚硫酸钠

利用二氧化钛催化氧化亚硫酸钠,研究催化剂等操作对亚硫酸钠氧化速率的影响。通过改变光照条件、通入空气流量、紫外线波长等因素,探究提高二氧化钛催化活性的原理。结果表明,二氧化钛在光照条件下可以催化氧化亚硫酸钠;使用紫外线照射会比在日光下催化剂的催化活性高;在使用254 nm的紫外光照射时比使用365 nm紫外光照射时的催化剂催化活性高;空气流量控制在1 L/min时,可以明显提高反应速率,加快亚硫酸钠的氧化速率。     

纳米二氧化钛光催化氧化在环境治理中的研究

介绍了6种纳米二氧化钛的制备方法,对其在大气环境治理以及污水处理中的研究进行了综述,目前的研究集中在紫外光激发催化氧化、以及影响催化氧化效率的因素分析上,而且发现薄膜化和负载型TiO2催化剂优于粉末状TiO2,并指出了进一步改性纳米二氧化钛的必要性,尤其是通过改性,提高可见光的利用率．以期在实践中推广应用。     

N-Zn/TiO2光催化氧化脱硫废液中亚硫酸钠的研究

采用溶胶凝胶法合成了氮、锌共掺杂二氧化钛催化剂（N-Zn/TiO₂）,用于催化氧化双碱法脱硫废液中的亚硫酸钠。通过X射线衍射、红外光谱、X射线光电子能谱和场发射环境扫描电镜对N-Zn/TiO₂催化剂的形貌和结构进行了表征。并考察了催化剂用量、溶液pH、空气流量、亚硫酸钠初始浓度对N-Zn/TiO₂光催化氧化亚硫酸钠的影响。实验结果表明：在不加N-Zn/TiO₂催化剂的情况下,将脱硫废液中的亚硫酸钠完全氧化需要8 h,而N-Zn/TiO₂在紫外光照射下能在1.5 h内将亚硫酸钠催化氧化完全。催化剂的用量对反应速率的影响最大,废液中亚硫酸钠的氧化速率随着催化剂用量的增多呈上升趋势。其次是溶液的pH对亚硫酸钠的氧化有较大影响,随着pH的增大,亚硫酸钠的氧化速率呈先增大后减小的趋势。实验所得到的最优反应条件为：催化剂用量为m（催化剂）/m（亚硫酸钠）=1/100,pH=6.5,空气流量为4 L/min。     

二氧化钛光催化氧化技术的研究进展

在阐明光催化氧化反应机理的基础上分析了国内外TiO2光催化氧化反应的研究现状。提出目前国内外主要是从TiO2负载基材、TiO2光催化剂的修饰、改性以及TiO2光催化反应的影响参数几个方面进行研究,指出某些掺杂金属或非金属的TiO2光催化剂可使TiO2薄膜的吸光范围拓宽至可见光区,具有良好的应用前景。     

半导体二氧化钛光催化氧化的研究进展

介绍了二氧化钛光催化氧化的基本原理,分析了光催化氧化的影响因素。阐述了光催化剂的固定方法及降解有机污染物的现状及发展方向,并提出了光催化氧化技术未来的发展趋势。     

二氧化钛光催化材料

介绍了 Ti O2 光催化材料光催化氧化和表面超亲水性的原理 ,并对其在空气净化 ,杀菌 ,表面防雾、自清洁等方面的应用作了简要评述     

纳米三氧化二镧-二氧化钛光催化活性的研究

采用溶胶-凝胶法制备纳米三氧化二镧-二氧化钛粉体,以X-射线粉末衍射(XRD)、透射电子显微镜(TEM)、循环伏安(I-V)、红外光谱(FTIR)、紫外-可见光谱(UV-VIS)等对纳米三氧化二镧-二氧化钛粉体的表征来研究纳米三氧化二镧-二氧化钛粉体的表面结构与光催化活性。光降解亚甲基蓝实验结果表明了在二氧化钛中加入质量分数1%的三氧化二镧后,比单一的二氧化钛具有更高的光降解活性。     

TiO2光催化氧化亚甲基蓝的动力学研究

探讨了二氧化钛（TiO2）光催化氧化亚甲基蓝水溶液的动力学规律。结果表明,该反应符合Langmuir-Hin-shelwood（L-H）动力学模型,且光催化氧化过程为一级反应,反应速率常数（k）与亚甲基蓝初始浓度（c0）的关系是k∝c0^-1.1805。反应前后的紫外可见图谱和红外图谱表明,·OH破坏了亚甲基蓝的结构。     

纳米二氧化钛光催化涂料降解甲醛的研究进展

介绍了纳米二氧化钛光催化降解甲醛的机理,着重讨论了不同因素下二氧化钛对甲醛光催化降解的影响及提高TiO2光催化活性的途径,概述了纳米二氧化钛光催化降解甲醛的研究进展。     

The comparative studies of titanium dioxide in gas-phase ethanol photocatalytic oxidation by the FTIR in situ method

Gas-phase ethanol photocatalytic oxidation on the series of TiO₂ samples has been studied by the FTIR in situ method. The TiO₂ samples were prepared by the usual method and they possessed similar physicochemical properties (porosity, specific area), but were found to have different photocatalytic activities. The acidity and concentration of the Lewis centers have been measured. The TiO₂ photocatalytic activity has been found to correlate with the surface acidity, and the Ti³⁺ and carbonate surface concentrations.     

Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes

The TiO₂ nanotubes have demonstrated potential in the photoelectrocatalytic degradation of methyl orange dye (MO). TiO₂ nanotubes were prepared using anodization of titanium foils in phosphoric acid (PA) and ethylene glycol (EG) by mechanical stirring and ultrasonic method. The TiO₂ nanotubes prepared in EG under ultrasound followed by annealing in nitrogen atmosphere showed higher activity towards dye degradation as compared to the stirring method. Dye degradation shows improved activity under an external bias compared to degradation performed in the absence of an external bias. An increase in the external bias from +0.0 to +0.1 V versus calomel electrode (SCE) is sufficient to improve the degradation rates of MO from 22% to 57% within the first 10 min. At +0.1 V, a complete degradation of 40 μM MO is observed within 30 min. The addition of oxidants such as oxygen and hydrogen peroxide demonstrate improvement in the MO degradation.     

Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes

The TiO₂ nanotubes have demonstrated potential in the photoelectrocatalytic degradation of methyl orange dye (MO). TiO₂ nanotubes were prepared using anodization of titanium foils in phosphoric acid (PA) and ethylene glycol (EG) by mechanical stirring and ultrasonic method. The TiO₂ nanotubes prepared in EG under ultrasound followed by annealing in nitrogen atmosphere showed higher activity towards dye degradation as compared to the stirring method. Dye degradation shows improved activity under an external bias compared to degradation performed in the absence of an external bias. An increase in the external bias from +0.0 to +0.1 V versus calomel electrode (SCE) is sufficient to improve the degradation rates of MO from 22% to 57% within the first 10 min. At +0.1 V, a complete degradation of 40 μM MO is observed within 30 min. The addition of oxidants such as oxygen and hydrogen peroxide demonstrate improvement in the MO degradation.     

Kinetics of the gas-solid heterogeneous photocatalytic oxidation of trichloroethylene by near UV illuminated titanium dioxide

Kinetics of the gas/solid heterogeneous photocatalytic oxidation of dilute trichloroethylene (TCE) vapors by ultraviolet-illuminated titanium dioxide have been determined using a fixed-bed dynamic photoreactor. Reaction rate dependences on inlet TCE, oxygen and water vapor concentrations were found to consist of both reactant sensitive and insensitive regions. In the reactant sensitive regions, measured limiting apparent reaction rate orders for TCE, oxygen and water vapor are 0.8, 1.7 and — 3, respectively. Water vapor in the reactant stream lowersinitial reaction rates relative to corresponding water free conditions, but is required to sustain photocatalytic activity for extended periods of time.     

TiO2在不同基质上光催化活性的比较

研究了不同基质对纳米TiO2光催化活性的影响。采用甲基橙作为脱色对象,以脱色速率常数作为衡量光催化活性的标准,发现金属基质更有效,且对TiO2光催化活性有明显的协同作用,其中在镀锌白铁基质上的光催化效率最高。     

Hydrothermal synthesis of titanium dioxide using acidic peptizing agents and their photocatalytic activity

We have prepared TiO₂ nanoparticles by the hydrolysis of titanium tetraisopropoxide (TTIP) using HNO₃ as a peptizing agent in the hydrothermal method. The physical properties of nanosized TiO₂ have been investigated by TEM, XRD and FT-IR. The photocatalytic degradation of orange II has been studied by using a batch reactor in the presence of UV light. When the molar ratio of HNO₃/TTIP was 1.0, the rutile phase appeared on the titania and the photocatalytic activity decreased with an increase of HNO₃ concentration. The crystallite size of the anatase phase increased from 6.6 to 24.2 nm as the calcination temperature increased from 300 °C to 600 °C. The highest activity on the photocatalytic decomposition of orange II was obtained with titania particles dried at 105 °C without a calcination and the photocatalytic activity decreased with increasing the calcination temperature. In addition, the titania particles prepared at 180 °C showed the highest activity on the photocatalytic decomposition of orange II. This paper was prepared at the 2004 Korea/Japan/Taiwan Chemical Engineering Conference held at Busan, Korea between November 3 and 4, 2004.     

氮掺杂对二氧化钛光催化性能的影响

采用溶胶-凝胶法,以硝酸铵为氮源,制备了氮掺杂二氧化钛薄膜,通过紫外可见吸收光谱(UV-VIS)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)对氮掺杂二氧化钛进行表征,并以亚甲基蓝为降解模型,探讨了氮掺杂对二氧化钛光催化性能的影响。结果表明:当氮掺杂量为11%、煅烧温度为450℃时,其吸收光谱明显发生红移,样品的光催化活性最好。随着氮掺杂量的增加,薄膜的催化性能先增后减,主要原因是氮掺杂会影响晶相颗粒的生长和产生缺陷,薄膜表面更加粗糙,比表面积增大。煅烧温度对薄膜的催化性能的影响也呈现先增后减,因为煅烧温度会影响二氧化钛晶型的转变和结晶度的变化。     

纳米二氧化钛光催化降解水中有机污染物的研究

Ti0     

提高二氧化钛光催化性能的研究进展

对过渡金属离子掺杂、贵金属表面沉积、表面光敏化、表面超强酸化等几种提高TiO2 光催化剂活性的方法进行了综述 ;介绍了近年来为了提高TiO2 光催化过程的效率 ,而发展形成的微波场作用下光催化反应、热催化与光催化的耦合反应、室温等离子体光催化反应、生物光催化反应、电场助光催化反应等几种新型高效光催化反应技术的研究现状与进展 ;并对TiO2 光催化的应用进行了展望。     

纳米SiO_2的表面改性

分别用吐温-80、油酸、十二烷基苯磺酸钠、硅烷偶联3-氨丙基三乙氧基硅烷(KH550)和硅烷偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)处理纳米二氧化硅,用沉降体积和亲油化度来对比改性效果,结果表明KH570改性效果最好,其最佳工艺条件为:KH570用量为8%,反应温度为70℃,反应时间为2 h,反应pH为5.5。对KH570改性前后的纳米粉体进行了红外光谱分析、热重分析、紫外-可见光谱分析、扫描电镜分析等表征。结果表明,硅烷偶联剂与纳米二氧化硅之间形成了化学结合,改性后的纳米SiO_2分散性提高,从而更好地应用于聚合物材料中。