Ag负载WO3/TiO2光催化剂的合成及其催化性能

以钛酸丁酯、无水乙醇、钨酸铵为原料,采用溶胶-凝胶法合成了WO3/TiO2复合光催化剂;采用光还原技术制备了Ag负载WO3/TiO2光催化剂,借助X射线粉末衍射(XRD)和UV-Vis光谱等技术对样品的组成和光吸收性能进行了表征,并以罗丹明B为模型污染物考察样品的光催化活性。XRD分析表明,所得粉体均为锐钛矿型纳米TiO2,且与WO3复合后,纳米TiO2特征衍射峰宽化,强度降低;UV-Vis光谱分析表明,载银使得催化剂在400—700nm的可见光区域对光响应,且在紫外光区吸收显著增强,对光具有更高的利用率;以罗丹明B为降解物的光催化实验表明,WO3复合对纳米TiO2光催化活性有显著的影响,而载Ag后其光催化活性进一步提高,将该光催化剂用于炼油厂废水的处理,效果较好。     

Pr掺杂TiO2光催化剂的制备及其对酸性品红降解反应的催化性能

以钛酸四丁酯为前躯物,采用溶胶-凝胶法制备了掺杂不同含量Pr的TiO2光催化剂,利用XRD,TG-DTA,AFM,UV-Vis,FTIR等手段对催化剂进行了表征。并通过酸性品红光催化降解实验对其光催化性能进行了评价,考查了实验条件,如催化剂用量,烧结温度,掺杂量等对催化剂催化活性的影响。Pr2O3的掺杂阻碍了TiO2晶相由锐钛矿型向金红石型的转变,使TiO2的粒径减小,比表面积增大,催化活性增强。当Pr掺杂量为0.8%,催化剂用量为0.03g,烧结温度为500℃时,酸性品红的降解率达到97%以上,酸性品红的降解反应为准一级反应。     

纳米复合材料TiO2-ZrO2光催化降解可溶性染料的研究

采用溶胶-凝胶方法将光催化剂TiO2和ZrO2复合,再经700℃灼烧5h后获得了纳米复合光催化材料TiO2-ZrO2.该材料经XRD检测具有光催化活性良好的晶型结构.TEM测定结果显示产物的平均粒径约为20nm.通过对可溶性染料刚果红等的光催化降解实验证明,该复合材料具有较高的光催化活性.     

Ag-TiO_2/KIT-6复合纳米光催化剂的研究

以有序介孔SiO2(简称KIT-6)为载体,采用钛酸丁酯水解法将纳米TiO2与KIT-6复合,并通过沉积沉淀法将纳米Ag粒子负载于其上,首次制得Ag-TiO2/KIT-6复合光催化剂,并采用相同的方法制备了一系列相关的催化剂.以光催化降解甲基橙来评价其催化性能,光催化活性顺序为Ag-TiO2/KIT-6＞Ag/TiO2＞TiO2/KIT-6＞TiO2＞Ag/KIT-6.利用XRD、N2物理吸附、XPS、UV-Vis DRS和TEM对系列催化剂进行表征,结果表明Ag-TiO2之间形成的异质结和催化剂的大比表面积是Ag-TiO2/KIT-6具有最高光催化活性的重要原因.其中Ag-TiO2之间的异质结结构,有效抑制了光生电子和光生空穴在TiO2表面和体相内部的复合,提高了光催化活性;此外Ag-TiO2/KIT-6的大比表面积大大提高了催化剂的吸附能力,增加了催化剂与污染物的接触,达到快速光催化降解污染物的目的.     

TiO2/SnO2复合光催化剂的制备及性能

采用特殊液相沉淀法制备纳米级的TiO2/SnO2复合粒子,对制备的纳米TiO2/SnO2采用XRD、TEM等手段进行了表征。用它做催化剂在日光下对甲基橙溶液进行了光催化实验。结果表明,纳米级TiO2/SnO2复合催化剂比纯TiO2的催化活性好,当SnO2摩尔百分数为20%时效果最佳,在60min内对10mg/L的甲基橙水溶液的降解率高达90.2%,具有较好的光催化活性。     

铁镧复合氧化物纳米米微粒的制备及其光催化性能

以溶胶-凝胶法制备了纳米铁镧复合氧化物.通过了XRD、TG-DTA等手段,对该氧化物进行了分析.研究了焙烧温度、光催化剂的用量、光照等因素对催化剂光催化降解活性染料的影响.并用红外光谱分析方法验证光催化降解效果.结果表明在适当的用量和700C焙烧并在紫外光照射下铁镧复合氧化物对活性翠蓝KGL和活性B-GFF黑有较强的光催化降解活性.     

铁镧复合氧化物纳米微粒的制备及其光催化性能

以溶胶-凝胶法制备了纳米铁镧复合氧化物。通过了XRD、TG-DTA等手段,对该氧化物进行了分析。研究了焙烧温度、光催化剂的用量、光照等因素对催化剂光催化降解活性染料的影响。并用红外光谱分析方法验证光催化降解效果。结果表明在适当的用量和700℃焙烧并在紫外光照射下铁镧复合氧化物对活性翠蓝KGL和活性B-GFF黑有较强的光催化降解活性。     

Cu-Fe-TiO2/膨润土复合光催化剂的表征及性能

以膨润土为载体,用溶胶-凝胶法制备了不同焙烧温度的Cu-Fe双金属掺杂的TiO2/膨润土复合光催化剂,采用XRD、TG-DSC和N2吸附技术对其结构进行了表征,通过光催化降解直接天蓝染料废水,考察了焙烧温度对催化剂光催化性能的影响.结果表明,当焙烧温度高于300℃时,催化剂中出现了锐钛矿型TiO2,掺杂的Cu2+、Fe3+可能进入了TiO2晶格取代了部分Ti4+,使其晶格产生了一定程度的畸变,形成了复合半导体,拓宽了TiO2的光谱响应范围,并且Cu2+、Fe3+掺杂的TiO2复合半导体进入了蒙脱石层间,与膨润土成功复合,增大了催化剂的比表面积并改善了催化剂的孔体积,提高了光催化剂活性和再生性.     

不同干燥法制备纳米TiO2光催化剂的光谱研究

本文分别用常态、超临界乙醇和超临界CO2干燥法干燥钛酸正丁酯的醇凝胶，制备纳米TiO2光催化剂。应用XRD，FTIR，FT－Raman和Fluorescent spectrum(FS)等光谱技术对催化剂进行了表征。以光催化降解罗丹明B为模型反应，比较所得样品光催化活性。实验结果表明，不同干燥方法对催化剂的晶相结构、半导体能带结构、光吸收性能、表面性质及光催化活性均产生显著的影响，用超临界CO2干燥法制备的TiO2光催化剂具有较好的光催化活性。     

RuO2/TiO2/漂珠复合光催化剂的制备及性能

"利用RuO2/TiO2前驱体溶胶,采用溶胶-凝胶-浸渍法在漂珠(FP)表面沉积RuO2/TiO2膜,经120 ℃干燥、500 ℃焙烧制备复合光催化剂RuO2/TiO2/FP,并通过SEM、XRD以及FT-IR分别对其结构进行了表征． 结果表明,RuO2/TiO2膜的平均厚度(三层)约1 1m,膜材料中TiO2主要呈现锐钛矿型结构,而RuO2是以非晶态高度分散在粒子表面．以高效氯氰菊酯杀虫剂的光催化降解为模型反应,研究了RuO2/TiO2/FP的光催化性能,探讨了影响催化剂活性的因素及采用太阳光做光源处理     

Investigation on transition crystal of ordinary rutile TiO2 powder and its sonocatalytic activity

The transition crystal TiO(2) sonocatalyst was prepared utilizing the method of ultrasonic irradiation in hydrogen peroxide solution. The sonocatalytic activity of the transition crystal TiO(2) powder was validated through the degradation of methyl orange in aqueous solution by ultrasonic irradiation. The results show that the sonocatalytic activity of the transition crystal TiO(2) powder is obviously higher than that of pure rutile and anatase TiO(2) powders as well as mixed rutile and anatase TiO(2) powders according to the proportion of corresponding transition crystal TiO(2) catalyst. The degradation ratio of methyl orange in the presence of the transition crystal TiO(2) catalyst surpasses 75% within 80 min ultrasonic irradiation, while the degradation ratios are 55.93%, 51.68% and 40.88%, respectively, for rutile, mixed and anatase TiO(2) powders.     

二氧化钛薄膜的结构和光催化活性关系

用化学气相沉积法合成了具有不同晶体结构的二氧化钛薄膜，研究了二氧化钛薄膜的结构和光催化活性的关系．用XRD、AFM研究了薄膜的晶体组成和形貌，用亚硝酸根研究了薄膜的光催化活性．结果表明在制备温度低于573 K或高于773 K时，薄膜的结构分别为锐钛矿型或金红石型．而在上述温度之间生成的薄膜具有混合的晶型结构，特别是在623 K附近，制备的薄膜具有最高的光催化活性．进一步研究表明，当金红石与锐钛矿微晶体的比例在0.5?0.7时，催化剂薄膜具有高活性．     

Investigation on the sonocatalytic degradation of acid red B in the presence of nanometer TiO2 catalysts and comparison of catalytic activities of anatase and rutile TiO2 powders

Here, the nanometer anatase and rutile titanium dioxide (TiO(2)) powders were introduced to act as the sonocatalysts during the ultrasonic degradation of azo dye-acid red B which was chosen as model compound. The ultrasound of low power was used as an irradiation source to induce TiO(2) particles performing catalytic activity. It was found that the processes of sonocatalytic degradation were different between nanometer anatase TiO(2) and nanometer rutile TiO(2). For nanometer anatase TiO(2) catalyst, the acid red B was mainly oxidated by the holes on the surface of nanometer anatase TiO(2) particles, so that the decolorization and degradation happened at the same time. For the nanometer rutile TiO(2) catalyst, the acid red B was mainly oxidated by the *OH radicals from the ultrasonic cavitation, so that the decolorization of azo bond takes place primarily, and then the degradation of naphthyl ring does. The intermediates of acid red B in the presence of nanometer anatase and rutile TiO(2) powders have been monitored by UV-vis spectra and high performance liquid chromatography (HPLC), respectively. All experiments indicated that the degradation effect of acid red B in the presence of nanometer anatase TiO(2) powder was obviously better than that in the presence of nanometer rutile TiO(2) powder. Hence, the method of sonocatalytic degradation for organic pollutants in the presence of nanometer anatase TiO(2) powder is expected to be promising as an advisable choice for the treatment of organic wastewaters in future.     

Investigation on the transition crystal of ordinary rutile TiO2 powder by microwave irradiation in hydrogen peroxide solution and its sonocatalytic activity

The transition crystal TiO(2) catalyst with high sonocatalytic activity was obtained utilizing the microwave irradiation in hydrogen peroxide solution. At the same time a series of affecting factors (microwave irradiation time, heat-treated time and heat-treated temperature) to prepare the TiO(2) catalyst on the sonocatalytic degradation of parathion were considered in this paper. The ultrasound of low power was used as an irradiation source to induce treated TiO(2) particles to perform catalytic activity. The results show that the sonocatalytic activity of the transition crystal TiO(2) powder is obviously higher than those of pure ordinary rutile and anatase TiO(2) powders. At last, the parathion in aqueous solution was degraded completely and became some simple inorganic ions such as NO(3)(-), PO(4)(3-), SO(4)(2-), etc. The degradation ratio of parathion in the presence of the transition crystal TiO(2) catalyst attains nearly 80% within 60 min ultrasonic irradiation, while corresponding ones are only 65.23% and 53.88%, respectively, for pure ordinary rutile and anatase TiO(2) powders.     

Sonocatalytic degradation of methyl orange in the presence of TiO2 catalysts and catalytic activity comparison of rutile and anatase

Rutile and anatase titanium dioxide (TiO(2)) powders were used as sonocatalysts for the degradation of methyl orange which was used as a model compound. Ultrasound was used as an irradiation source. It was found that the sonocatalytic degradation ratios of methyl orange in the presence of TiO(2) powder were much better than ones without any TiO(2), but the sonocatalytic activity of rutile TiO(2) particles was obviously higher than that of anatase TiO(2) particles. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results show that the best degradation ratio of methyl orange can be obtained when the experimental conditions of the initial methyl orange concentration of 10 mg/l, rutile TiO(2) added amount of 500 mg/l, ultrasonic frequency of 40 kHz, output power of 50 W, pH=3.0 and 40 degrees C within 150 min were adopted. In addition, the catalytic activity of reused rutile TiO(2) catalyst was also studied and found to be better than new rutile TiO(2) catalyst sometimes. All experimental results indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO(2) powder was an advisable choice for treating non- or low-transparent organic wastewaters.     

铁掺杂TiO2可见光催化降解溴酚蓝的动力学

用水热法制备了铁掺杂的TiO2晶体粉末,以SEM和XRD表征了样品的形貌和晶型,研究了在不同反应条件下TiO2晶体粉末对溴酚蓝的光催化降解的动力学过程.结果表明:所制备的TiO2晶体为锐钛矿型;可见光照射下,5 mg· L-1的溴酚蓝溶液,掺10％ Fe3+(摩尔分数)的催化剂用量0.0500 g,室温下恒温反应4h时...     

介孔二氧化钛光催化降解乙醛及其影响因素

"应用溶剂蒸发自组装的方法合成了具有蠕虫状孔道的介孔二氧化钛粉末和薄膜．考察了不同焙烧温度对材料介孔结构和光催化性能的影响．乙醛光催化降解实验用来表征不同焙烧温度下介孔材料的光催化性能．结果表明实验中合成的介孔二氧化钛材料的光催化活性明显高于颗粒二氧化钛(Degussa P25)．其中400 oC焙烧的样品具有平均孔径为6.0 nm的窄的孔径分布和117 m2/g的大的比表面积．通过对光催化活性结果的分析,发现介孔二氧化钛的活性主要受其比表面积和结晶性的共同影响．对介孔二氧化钛薄膜材料进行了同样的光催化表     

Reactive dye degradation by combined Fe(III)/TiO2 catalyst and ultrasonic irradiation: Effect of Fe(III) loading and calcination temperature

The development of Fe(III)/TiO(2) catalysts for sonocatalytic degradation of Reactive Blue 4 (RB4) dye in water was carried out using sol-gel method. Their surface morphology, phase transformation and surface characteristics were studied using SEM, XRD and surface analyzer, respectively. Phase transformation from amorphous to anatase occurred at 500°C and transformation of anatase to rutile phase occurred at 700°C. Complete rutile phase was formed at 900°C with corresponding increase in the particle size. Increasing in Fe(III) loading led to a reduction in the anatase phase and with the formation of weaker and broader of diffraction peaks. Surface morphology of the prepared catalyst was clearly observed with increasing calcination temperature. Surface area of the prepared catalyst decreased with increasing calcination temperature or increasing Fe(III) loading. The combination of 0.4 mol% of Fe(III)/TiO(2) with ultrasonic irradiation gave the highest sonocatalytic activity in the removal of RB4 from the aqueous solution. On the other hand, the presence of even small amount of rutile inhibited the catalytic activity of catalyst. 1.5 g/L was the optimum amount of catalyst that led to the highest sonocatalytic degradation of RB4 with an efficiency of 90%. Aeration significantly accelerated the reaction rate. Higher removal at 96% could be achieved with the combination of 0.4Fe(III)/TiO(2) and aeration under ultrasonic irradiation.