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1.
利用TiO_2薄膜光催化降解苯酚(英文)   总被引:2,自引:0,他引:2       下载免费PDF全文
利用化学气相沉积法制备TiO_2W薄膜,在光催化下降解苯酚溶液。研究结果表明,薄膜沉积条件与降解速率有关,且用硅片作底物,薄膜为锐态晶型时其降解苯酚速率最高。利用光电催化比只用光催化降解苯酚速率高约10%。用紫外光照射30分钟,苯酚最大可转化74%。  相似文献   

2.
二氧化钛的尺寸与光催化活性的关系   总被引:129,自引:3,他引:126  
采用溶胶-凝胶法控制制备了晶粒尺寸从10nm到80nm的二氧化钛纳米半导体.用光催化降解苯酚作为模型反应,结合XRD,DRS,FS等表征手段,研究了纳米TiO2的制备条件与其晶粒尺寸和相结构的关系,探讨了纳米TiO2尺寸效应对其光催化活性的影响.发现当晶粒尺寸小于16nm时,二氧化钛半导体具有了明显的尺寸量子效应.尺寸量子效应对提高TiO2光催化降解苯酚的催化活性起了极为重要的作用.  相似文献   

3.
TiO2光催化反应及其在废水处理中的应用   总被引:190,自引:1,他引:189  
TiO2多相光催化能利用太阳能有效降解多种对环境有害的污染物,使有害物质矿化为CO2、H2O及其它无机小分子物质。本文综述了TiO2光催化的机理,提高光催化能力的途径,多种具有代表性污染物的光催化降解处理方法,以及目前尚存在的一些问题,扼要介绍了近年来TiO2光催化反应及其在废水处理中应用的研究进展及应用前景。  相似文献   

4.
利用二氧化钛簿膜光催化降解废水(英文)   总被引:2,自引:0,他引:2       下载免费PDF全文
主要研究了在TiO2薄膜上光催化降解有机磷废水。结果表明,镀膜基片不同、光催化时间不同、TiO2晶型不同均对降解速率有影响。感兴趣的是可以利用太阳紫外光降解有机磷废水。  相似文献   

5.
TiO2光谱化反应及其在废水处理中的应用   总被引:77,自引:0,他引:77  
沈伟韧  赵文宽 《化学进展》1998,10(4):349-361
TiO多相光催化能利用太阳能有效降低多种对环境有害的污染物,使有害物质矿化为CO2、H2O及其它无机小分子物质。本文综述了TiO2光催化的机理,提高光催化能力的途径,多种具有代表性污染物的光催化降解处理方法,以及目前尚存在的一些问题,扼要介绍了近年来TiO2z光催化反应及其在废水处理中应用的研究进展及应用前景。  相似文献   

6.
TiO2薄膜光催化降解4-(2-吡啶偶氮)间苯二酚的研究   总被引:29,自引:3,他引:26  
为了探索有机物4-(2-吡啶偶氮)间苯二酚(PAR),在固定光催化剂上的降解行为,采用溶胶一凝胶法,在玻璃表面制得均匀透明的纳米TiO2薄膜,并以其作光催化剂,在254nm紫外光照射下,进行PAR水溶液的光催化降解研究。研究了PAR光催化降解率与溶液pH值、PAR初始浓度、助催化剂(H2O2)浓度和不同光照条件的变化关系,得出了TiO2薄膜的光催化降解PAR的有利条件。  相似文献   

7.
增强型电场协助光催化降解有机污染物   总被引:20,自引:1,他引:19  
以颗粒状TiO2为光催化剂,以工苯酚溶液的降解为模型反应,实现了在电场协助下三维光电组合仙化反应,实验发现,在相同的反应条件下,电解反应和光催化反应中苯酚的降解率分别为10%和33.6%,而光电组合催化过程中苯酚的降解率为82.8%,存在明显的协同作用,产生这种协同作用的主要原因是,电解水反应可有效地为光催化反应提供氧源,以及阳极偏压可有效地减少光生电子和空穴的复合,此外,还研究了电量和溶液酸碱性  相似文献   

8.
水面石油污染物的光催化降解   总被引:57,自引:1,他引:56  
制备了漂浮负载型TiO2光催化剂,并用XRD,BET,TEM和SEM等方法进行了表征。研究了这类催化剂对水面石油污染物的光催化降解,实验结果表明,掺杂Fe^3+的TiO2光催化剂具有高的光催化活性,经高压汞灯照射8h,水面原油降解75%。  相似文献   

9.
掺杂铈对玻璃表面TiO2薄膜上油酸光催化降解的影响   总被引:17,自引:0,他引:17  
采用旋转涂膜工艺,以溶胶-凝胶法在玻璃表面制备了掺杂铈的TiO2薄膜,利用高压液相色谱、紫外-可见光分光光度计、扫描电镜和能谱仪等手段对掺杂铈的TiO2薄膜者了表征,考察了掺杂铈对油酸光催化妥效率及TiO2薄膜表面晶粒分布的影响,并对薄膜的化学成分进行了定性和定量分析,结果表明,掺杂3%Ce的TiO2薄膜对油酸有最高的光催化降解效率,400℃为掺杂铈TiO2薄膜的最佳热处理温度。  相似文献   

10.
以空心玻璃微球为载体,采用浸涂法制备TiO2/beads光催化剂;利用X射线衍射、扫描电镜、热分析对TiO2/beads进行了表征.研究了不同制备条件对TiO2/beads光催化活性的影响.结果表明,热处理600℃,5h,A/R为81/19时,TiO2/beads光催化活性最高;样品由非晶向锐钛矿型转变的温度为429℃,当锐钛矿型TiO2与金红石型TiO2以一定的比例共存时,TiO2/beads的光催化活性较好  相似文献   

11.
The photodegradation of phenol was studied in the aqueous solutions over titania pillared zirconium phosphate and titanium phosphate under solar radiation and compared with that of the UV-radiation (6 W low pressure Hg vapor lamp). This reaction was studied by varying different parameters such as catalyst dose, initial phenol concentration, pH of solution and irradiation time. The degradation rate of phenol was favourable under neutral pH condition. The degradation process approximately obeyed first-order kinetics with apparent rate of degradation constant increasing with decreasing the initial phenol concentration.  相似文献   

12.
The photocatalytic degradation of chlorophenols was evaluated under direct solar radiation using commercial ZnO catalyst. Effects of several parameters such as a catalyst loading, pH of solution and initial concentration on the degradation process have been investigated. The photocatalytic degradation efficiency of chlorophenols at the optimum value of the parameters was compared under similar experimental conditions. The results of efficiency and mineralization showed the degradation of 2-chlorophenol and 2,4-dichlorophenol compound with the first order kinetic rate and the rate constant decreases as the initial concentration of the chlorophenols increase. However, the rate constant was strongly affected by type of chlorophenols compound present either 2-chlorophenol or 2,4-dichlorophenol. The highest removal of chlorophenols was obtained after 120 min and the final intermediate compounds of chlorophenols degradation are lower molecular weight compound consisting of acetic acid which was analyzed through the HPLC.  相似文献   

13.
The photocatalytic degradation of an azo reactive dye, Reactive Yellow 84 (RY84), in aqueous solutions using industrial titanium dioxide coated non-woven paper was studied. The experiments were carried out to investigate the factors that influence the dye photocatalytic degradation, such as adsorption, initial concentration of dye, temperature, and solution pH. The experimental results show that adsorption is an important parameter controlling the apparent kinetics constant of degradation. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model. The degradation was enhanced by the temperature and was favored in acidic pH range.  相似文献   

14.
苯乙酮的TiO2光催化降解及其影响因素   总被引:3,自引:0,他引:3  
在TiO2(Degussa P25)和波长大于350 nm的光作用下,水中苯乙酮(1×10-5~1×10-4mol/L)能发生光催化降解,生成邻羟基苯乙酮等中间产物.该降解过程遵循Langmuir-Hinshelwood动力学方程,降解速率随入射光强度的增强和溶液起始pH值的增大而增大,但反应温度的影响较小,其降解反应的表观活化能为4.2~6.4 KJ/mol.  相似文献   

15.
活性炭负载纳米TiO_2光催化降解甲醛废水研究   总被引:1,自引:0,他引:1  
甲醛对人和温血动物的毒性很强,如果人类长期饮用被甲醛污染的水源,会引发头昏、贫血以及各种神经系统疾病.为此,研究学者对甲醛废水的处理进行了很多的试验研究.目前处理甲醛废水的主要方法有:芬顿法、光催化氧化法、湿式氧化处理等高级氧化技术,二氧化氯法,蒸汽吹脱法,氧化吸附法,SBR工艺等.  相似文献   

16.
浅池型TiO2/ACF光催化降解水中苯酚的研究   总被引:4,自引:1,他引:3  
为了提高光催化过程的降解速率,本文以涂覆法制得的二氧化钛/活性炭纤维(TiO2/ACF)为光催化剂,300 W(365 nm)高压汞灯为光源,研究了浅池型反应器中苯酚在TiO2/ACF上的光催化降解动力学;探讨了光强度、高压汞灯滤光以及光源种类对降解反应的影响,并对光氧化,光催化和吸附过程进行了比较。结果表明:光氧化对苯酚的降解无效果,光催化降解速率常数与吸附速率常数之比为3.35/1;光强越大,光催化降解速率越快;高压汞灯不滤光时光催化降解速率明显加快,但光催化反应仍遵循准一级反应动力学方程;波长为254 nm紫外杀菌灯的降解效果高于波长为365 nm高压汞灯滤光后的降解效果。  相似文献   

17.
To investigate the influencing factors and the kinetics of photocatalytic degradation of phenol, experiments were carried out using conjugated polymer poly(fluorene-co-thiophene) (PFT) sensitized TiO2 and ZnO under LED (light-emitting diode) lights of the wavelength of 450–475 nm. Influencing factors, such as initial phenol concentration, photocatalyst dosage and pH value on the photocatalytic degradation of phenol were studied in detail. The reaction kinetics was found to follow pseudo first-order law.  相似文献   

18.
采用静电自组装法制备了复合材料K_8[Fe(H_2O)CdW_(11)O_(39)]/PANI/ZrO_2.运用UV,IR,XRD,SEM-EDS和N_2吸附-脱附的检测手段对其进行了表征,并以该化合物作为催化剂,研究了其对孔雀石绿溶液的光降解情况.通过实验确定最佳的光降解条件:孔雀石绿溶液的初始浓度为25mg/L,孔雀石绿溶液的初始pH值为2,K_8[Fe(H_2O)CdW_(11)O_(39)]/PANI/ZrO_2的用量为0.05g.在最佳的条件下,孔雀石绿溶液的脱色率可达98.68%.因此,K_8[Fe(H_2O)CdW_(11)O_(39)]/PANI/ZrO_2是一种光催化性能良好的复合材料.  相似文献   

19.
In this study, the photocatalytic degradation of oxytetracycline (OTC) in aqueous solutions has been studied under different conditions such as initial pollutant concentrations, amount of catalyst, and pH of the solution. Experimental results showed that photocatalysis was clearly the predominant process in the pollutant degradation, since OTC adsorption on the catalyst and photolysis are negligible. The optimal TiO2 concentration for OTC degradation was found to be 1.0 g/L. The apparent rate constant decreased, and the initial degradation rate increased with increasing initial OTC concentration with the other parameters kept unchanged. Subsequently, data obtained from photocatalytic degradation were used for training the artificial neural networks (ANN). The Levenberg–Marquardt algorithm, log sigmoid function in the hidden layer, and the linear activation function in the output layer were used. The optimized ANN structure was four neurons at the input layer, eighteen neurons at the hidden layer, and one neuron at the output layer. The application of 18 hidden neurons allowed to obtain the best values for R2 and the mean squared error, 0.99751 and 7.504e–04, respectively, showing the relevance of the training, and hence the network can be used for final prediction of photocatalytic degradation of OTC with suspended TiO2.  相似文献   

20.
The main objective of this research is to use the photocatalytic properties of PES/TiO2 nanofibers membranes to remove the phenol as a toxic pollutant in various effluents. The uniform fibers in terms of minimum bead formation and fibers diameter were fabricated. Therefore, more TiO2 catalysts are on the surface of the fibers which increase the active surface area of nanoparticles and consequently improve the phenol degradation efficiency. The effects of TiO2 concentration on hydrophilicity, mechanical properties, porosity, mean pore size, and water flux of membranes were studied. The PES/TiO2 nanofibers were evaluated for phenol degradation under UVA irradiation through a transparent membrane module. The amount of removable phenol was analyzed with high‐performance liquid chromatography. Central composite design was used as a statistical experimental design. Finally, the effect of TiO2 content in nanofibers and initial phenol concentrations were investigated as well as pH values in synthetic wastewater, on phenol degradation. The results from analysis of variance (ANOVA) analysis indicated that TiO2 content in nanofibers was the most important and effective parameter on phenol degradation. It was also presented that there is no significant interaction between parameters so that the effect of each parameter was investigated separately. Maximum phenol degradation was 43.0 ± 0.3% and found under conditions of TiO2 content, initial phenol concentration, and pH value of 8%, 120 ppm, and 7, respectively.  相似文献   

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