纳米TiO2改性内墙乳胶漆降解甲醛的研究

主要研究了利用TiO2光催化作用对传统内墙乳胶漆改性,并进行降解甲醛实验的研究。研究结果表明,改性乳胶漆能显著提高降解甲醛的能力。     

纳米TiO_2光催化降解空气中甲醛的研究

针对室内空气污染现状,选用室内空气污染的"头号杀手"甲醛作为研究对象,结合光催化和纳米技术,模拟合理的室内环境,将制备成功的纳米TiO2在紫外线照射下进行光降解处理,净化室内空气中的甲醛,并采用现行国家标准进行测试,效果良好。     

Cu-TiO2光催化降解甲醛气体的研究及应用

采用环境测试舱模拟可见光下的室内环境,以甲醛气体的光催化降解为探针反应,评价了通过纳米杂化和溶胶-凝胶技术制备的Cu-TiO2纳米晶体对甲醛气体的降解效果.用X射线衍射和紫外-可见分光光谱表征了掺杂纳米TiO2的晶体结构与光学性能.结果表明,Cu-TiO2在可见光源下具有比纯TiO2更好的光催化降解甲醛气体能力,并探讨了其在新型环保建材方面的应用.     

纳米TiO_2复合涂料的研制及其降解空气中甲醛的研究

用原位法合成硅丙乳液,添加纳米TiO2,进而研制成纳米TiO2复合硅丙涂料,经实验表明,该涂料具有良好的性能和较强的光催化降解室内空气中甲醛的能力,具有良好的市场前景。     

纳米TiO_2光催化降解室内空气中甲醛的影响因素初探

通过实验考察了环境温度、光照强度、TiO2浓度等因素对二氧化钛(TiO2)光催化降解甲醛的影响,结果表明:在一定范围内,环境温度升高,甲醛降解率提高;光照强度越强,甲醛降解率越高;TiO2浓度增大,能加快降解速度,但是对最终降解率无明显影响。     

纳米TiO2膜制备与光催化降解CHCl3

采用溶胶法制备纳米TiO2薄膜,其晶体为锐钛矿型,若加入PEG2000可使薄膜呈多孔状,并影响薄膜的透光率,纳米TiO2薄膜对CHCl3的光降解有很好的催化性能,而多孔状纳米TiO2薄膜的催化性能更优,光催化条件下的CHCl3分解率接近90%。     

纳米TiO_2膜制备与光催化降解CHCl_3

采用溶胶法制备纳米TiO2 薄膜 ,其晶体为锐钛矿型。若加入PEG 2 0 0 0可使薄膜呈多孔状 ,并影响薄膜的透光率。纳米TiO2 薄膜对CHCl3 的光降解有很好的催化性能 ,而多孔状纳米TiO2 薄膜的催化性能更优 ,光催化条件下的CHCl3 分解率接近 90 %。     

光催化处理甲醛废水的试验研究

甲醛是化学工业中常见的化学成分,对人类健康影响极大。利用纳米二氧化钛可分解甲醛,实现无害化处理。     

纳米TiO2粒子的研究

采用硫酸法钛白生产的中间产品硫酸氧钛(TiOSO4)为原料,以尿素为沉淀剂,经过均匀沉淀、胶溶、絮凝制备出纳米TiO2粒子.寻找出最佳的工艺条件反应温度98±2℃,反应时间2～3.5h,反应物摩尔配比为TiOSO4∶CO(NH2)2=2∶1,溶胶剂与偏钛酸浓度之比4∶1,絮凝剂用量为9.5mg/L;得到的纳米TiO2粒径为20～50nm,收率达92%.     

Ti/SnO2,Ti/SnO2-Sb2O3阳极电催化氧化酸性品红的试验研究

采用热氧化法制备了Ti/SnO2和Ti/SnO2-Sb2 O3电极,以酸性品红为研究对象,对两种电极材料进行了性能比较,考察槽电压、电流密度、电解质浓度对电催化氧化处理系统的影响.结果表明:热氧化法制备出的Ti/SnO2-Sb2 O3电极,其电催化性能明显优于Ti/SnO2电极;以Ti/SnO2-Sb2 O3为阳极,在酸性品红初始浓度为100 mg/L、电极间距为2.5 cm、电流密度为75mA/cm2、电解质浓度取12 g Na2SO4/L时,60 min后酸性品红的去除率达到了95.41％.     

Bi2MoO6/AgBr的制备及其光催化活性增强机制

采用水热法合成了Z型异质结Bi₂MoO₆/Ag Br光催化剂,利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、比表面积测试仪(BET)、稳态/瞬态荧光光谱仪等对其微观形貌、物相组成以及光电性能等特性进行表征;通过对目标污染物罗丹明B(Rh B)的降解分析该催化剂的活性和降解机理。结果表明,该催化剂由立方相的Bi₂Mo O₆纳米片堆叠而成的纳米微球和负载在其表面的Ag Br纳米花簇构成,异质结的形成使得比表面积增加了7.2 m²/g,光生电子对寿命延长。Bi₂Mo O₆与Ag Br复合后光催化活性明显提高,当Ag Br复合量为10%时效果最佳,光催化反应速率常数是Bi₂Mo O₆的1.6倍。当Rh B浓度为0.5×10^-5mol/L、Bi₂Mo O₆/Ag Br投加量为250 mg/L、p H值=7时,反应20 min后对Rh B的降解率可达到95.9%,且Bi₂Mo O₆/Ag Br经过5次循环实验后仍具有较高的光催化活性。自由基捕获实验结果表明,Bi₂MoO₆的主要活性基为·O₂^-,Bi₂Mo O₆/Ag Br的主要活性基团为·O₂^-和h⁺。根据以上实验结果,提出了一种由Ag⁰粒子为通道的Z型电荷转移机理。     

Photocatalytic transformation and mineralization of 2,4,6-trinitrotoluene (TNT) in TiO2 slurries

An analysis of the photodegradation of TNT in a TiO₂ slurry reactor is presented. The rates and extent of TNT transformation and mineralization are compared for photocatalytic and direct photolytic reactions under conditions of varying light energies and in the presence and absence of oxygen. Certain initial organic transformation products are identified for both photocatalytic and photolytic reactions. Nitrate, nitrite, and ammonium ions are analyzed and the possibility of semiconductor sensitization by colored compounds is considered. TNT was transformed rapidly under each set of photochemical conditions but destruction was faster and more complete with TiO₂ photocatalysis. Transformation by-products were destroyed readily under oxygenated photocatalytic conditions and were observed to be more refractory under direct photolytic conditions. Mass balances performed on carbon and nitrogen revealed that when the TiO₂ photocatalyst was utilized in the presence of oxygen and near u.v. radiation (λ > 340 nm) approx. 90% of the TNT was mineralized and 35% of the total nitrogen was recovered as ammonium ion after 120 min. Among the large number of organic transformation products produced photocatalytically, trinitrobenzoic acid, trinitrobenzene and trinitrophenol have been identified as oxidative intermediate species and dinitroaniline as a reduction product. The photocatalytic transformation of TNT appears to involve both oxidative and reductive steps and sensitization by colored compounds plays no detectable role in degradation.     

光化学、吸附和光催化对甲醛降解作用的对比研究

以甲醛为例,介绍了光化学反应、吸附作用和光催化氧化作用对挥发性有机化合物降解过程的作用机理;通过实验数据比较了以上三种作用对甲醛的降解效果;肯定了光催化氧化作用对甲醛降解的高效性;证明了将纳米半导体TiO2覆膜于普通滤料上,消除挥发性有机化合物以提高室内空气品质是完全可行的。     

高岭土负载氧化锌／氧化钛制备光催化功能材料的研究

以硫酸钛、硫酸锌、高岭土、尿素、无水乙醇等为原料,水热法制备了氧化锌／氧化钛复合纳米粉体以及高岭土负载纳米氧化锌／氧化钛复合粉体;利用X-射线衍射（XRD）对所得粉体进行了表征,研究了不同粉体对甲基橙溶液的光催化降解效果,制备出了光催化性能良好的高岭土负载纳米氧化锌／氧化钛复合粉体。     

TiO2光催化降解甲醛气体的研究

以玻璃纤维为载体,用溶胶-凝胶法自制锐钛矿型TiO2光催化材料,分别对400℃、450℃、500℃不同温度下制备的纳米TiO2进行X衍射(XRD)、电镜扫描(SEM)分析,并用在不同温度下制备的TiO2光催化材料进行降解甲醛的实验,结果表明450℃下制备的TiO2光催化材料具有最佳的光催化活性。     

Degradation of the antibiotic oxolinic acid by photocatalysis with TiO2 in suspension

In the work presented here, a photocatalytic system using titanium Degussa P-25 in suspension was used to evaluate the degradation of 20 mg L⁻¹ of antibiotic oxolinic acid (OA). The effects of catalyst load (0.2-1.5 g L⁻¹) and pH (7.5-11) were evaluated and optimized using the surface response methodology and the Pareto diagram. In the range of variables studied, low pH values and 1.0 g L⁻¹ of TiO₂ favoured the efficiency of the process. Under optimal conditions the evolution of the substrate, chemical oxygen demand, dissolved organic carbon, toxicity and antimicrobial activity on Escherichia coli cultures were evaluated. The results indicate that, under optimal conditions, after 30 min, the TiO₂ photocatalytic system is able to eliminate both the substrate and the antimicrobial activity, and to reduce the toxicity of the solution by 60%. However, at the same time, ∼53% of both initial DOC and COD remain in solution. Thus, the photocatalytical system is able to transform the target compound into more oxidized by-products without antimicrobial activity and with a low toxicity. The study of OA by-products using liquid chromatography coupled with mass spectrometry, as well as the evaluation of OA degradation in acetonitrile media as solvent or in the presence of isopropanol and iodide suggest that the reaction is initiated by the photo-Kolbe reaction. Adsorption isotherm experiments in the dark indicated that under pH 7.5, adsorption corresponded to the Langmuir adsorption model, indicating the dependence of the reaction on an initial adsorption step.