Photocatalytic activity and kinetics for acid yellow degradation over surface composites of TiO_2-coated activated carbon under different photocatalytic conditions

TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate.

A Novel High Active TiO_2/AC Composite Photocatalyst Prepared by Acid Catalyzed Hydrothermal Method

A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra （DRS） revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.

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。

超临界乙醇流体制取活性炭-TiO_2光催化剂复合材料的研究

研究表明 :在超临界乙醇流体介质下钛酸异丙酯能有效地分解成具光催化活性的锐钛矿型TiO2 粒子 ,同时产生的TiO2 粒子可与活性炭融合成一体 ,形成的活性炭 TiO2 光催化剂复合材料具很好的光催化活性与吸附作用 ,而且具有的协同效应优于活性炭与TiO2

Carbon nanotubes/TiO_2 nanotubes composite photocatalysts for efficient degradation of methyl orange dye

A series of carbon nanotubes/TiO2 nanotubes （CNTs/TNTs） composite photocatalysts were successfully prepared by incorporation of CNTs in HNO3 washing process. These photocatalysts were characterized by XRD, N2 physical adsorption, UV-vis diffuse reflectance spectroscopy, TEM and Raman spectroscopy, respectively, and their photocatalytic activities were tested by using methyl orange （MO） as a model compound. Also, the effects of amount of CNTs incorporated, calcination temperature and amount of catalyst on the photocatalytic activity of the composite photocatalyst were systematically investigated. The results show that the CNTs/TNTs composite exhibits much higher photocatalytic activity than that of the TNTs or CNTs alone.

新型双功能复合电极的制备及其加速水中有机污染物降解作用的研究

介绍了新型复合电极的制备方法、其双功能特性以及在提高水中有机污染物 (如苯胺 )降解速度所起的作用 ,并对其作用机制进行了讨论 .实验结果表明 ,由空气电极和 Ti O2 光催化剂组成的复合电极 ,当其工作电位控制在 0 .0 5 V(vs.SCE)左右时 ,既具有良好的光电效应 ,又具有以较高效率合成 H2 O2 的特性 ,使溶液中的有机分子获得来自光催化氧化与光化学氧化两方面的联合降解作用 。