纳米Fe2O3靶向鸡肉腐败菌光催化抑菌效能 特性研究

目的探索可见光下纳米Fe2O3对鸡肉腐败菌的光催化抑菌效能特性及机制。方法以Escherichia coli及鸡肉腐败菌Pseudomonas fluorescens和Macrococcus caseolyticus为受试菌株,可见光照为激发条件,研究纳米Fe2O3对细菌菌落数量和菌体脂质氧化程度的影响。结果纳米Fe2O3在可见光下能够有效抑制E.coli、P.fluorescens和M.caseolyticus生长繁殖,1.2 mmol/L的H2O2能够增强Fe2O3的光催化抑菌活性;当Fe2O3质量浓度为0.4 g/L时,对P.fluorescens和M.caseolyticus的抑菌作用效果最强;在光催化过程中,P.fluorescens和M.caseolyticu的脂质氧化值随着反应时间延长呈先升高后降低的趋势,在120 min分别达到最大值1.31nmol/mg(细胞干重)和2.14 nmol/mg(细胞干重)。结论可见光条件下,M.caseolyticus对光催化反应比P.fluorescens更加敏感,纳米Fe2O3先引起细菌体内脂质氧化,进而导致菌体细胞破裂而死亡。     

Influence of pH,concentration of sodium lactate as an additive and ultrasonic treatment on synthesis of zinc phosphate white pigments

Zinc oxide that has the photocatalytic activity is used as a white pigment for cosmetics. A certain degree of sebum on the skin is decomposed by the ultraviolet radiation in sunlight. In this work, zinc phosphates were prepared from zinc nitrate and phosphoric acid at pH 5 and 7 with and without the addition of sodium lactate and ultrasonic treatment as a novel white pigment for use in cosmetics. The chemical composition, powder properties, photocatalytic activity, colour phase, moisture retention and smoothness of the zinc phosphates were studied. The obtained materials had a Zn/P ratio of about 1.5, which corresponds to zinc orthophosphate Zn₃(PO₄)₂. Samples prepared with ultrasonic treatment indicated the high ratios of large particles in scanning electron microscopy images and particle‐size distributions. The photocatalytic activity of these zinc phosphate particles was too less to protect the sebum on the skin. The materials obtained and their thermal products at 100°C showed a high reflectance within the range of visible light. The slipping resistance and roughness of the powder were enough low for use in cosmetics.     

Si掺杂TiO2光催化材料的制备、活性及其机理

采用两步溶胶-凝胶法制备了Si掺杂TiO2(Si:TiO2)粉体,通过X射线衍射、热重-差热分析和X射线光电子能谱表征了Si:TiO2粉体样品的晶相及表面结构,以甲基橙为目标物考察了Si掺杂TiO2的光催化活性.研究发现:Si:TiO2粉体在水中降解有机物时,比纯TiO2粉体具有更高的光催化活性;Si:TiO2粉体具有...     

柠檬酸络合法制备可见光响应型光催化剂CuO/BiVO4

以Bi（NO3）3·5H2O和NH4VO3为原料,采用柠檬酸络合法制备新型可见光响应型复合光催化剂CuO/BiVO4。借助X射线衍射、全谱直读等离子体发射光谱仪、X射线光电子能谱仪、扫描电子显微镜、透射电子显微镜和紫外–可见漫反射光谱等表征粉体的结构和性能。结果表明：不同Cu摩尔掺量的复合光催化剂仍保持纯单斜晶系白钨矿...     

掺铈氧化钛薄膜的光催化性能

用射频磁控溅射法制备不同Ce摩尔（下同）掺量的氧化钛薄膜。X射线衍射分析结果显示：薄膜晶型主要为锐钛矿,随着Ce掺量的增加,二氧化钛锐钛矿相特征峰右移。紫外–可见分光光度计测定结果表明：随着Ce掺量的提高,薄膜吸收边出现红移。X射线光电子能谱分析表明：部分Ti4＋被还原成Ti3＋,大部分Ce4＋转化成Ce3＋。不同Ce...     

以玻璃珠为载体的负载型二氧化钛的制备及光催化活性研究

在溶胶-凝胶法制备。TiO2胶体溶液的基础上,用玻璃珠作载体制备了负载型TiO2光催化剂,利用SEM对玻璃珠载体和玻璃珠负载TiO2膜的粒径进行了表征分析;同时对玻璃珠负载TiO2的光催化活性进行了研究。     

UiO-66复合材料用于典型有机污染物吸附和光催化氧化的研究进展

UiO-66系列金属有机骨架（MOFs）材料因具有较高的比表面积、丰富的孔结构、优异的结构稳定性和类半导体特性而广泛应用于污染物的吸附和催化领域。文中指出：液相有机污染物主要通过物理吸附、静电、氢键、π-π相互作用被UiO-66基材料吸附去除,同时由于电性等性质差异,UiO-66基材料可从性质差异显著的多种有机污染物中选择性吸附污染物,而气相有机污染物主要通过氢键或UiO-66基材料孔道被吸附去除,同时环境中的水汽对污染物的吸附去除具有显著影响;针对光催化,由于载流子的快速复合,纯UiO-66基材料具有较低的光催化活性,通过与半导体材料复合可显著提高材料载流子分离速率,同时活性位点高度均匀分散在UiO-66基材料表面,利于光的激发及污染物与活性位点的充分接触,进而显著提高材料的光催化活性。与此同时,本文也提出了UiO-66基材料在有机污染物吸附和去除中的不足之处。最后展望了UiO-66基材料的发展前景。     

Photocatalytic and antimicrobial efficacy of PVDF/TiO2 membranes fabricated by solution blow spinning

With its ability to purify water and treat wastewater, photocatalytic membranes have become a promising solution. The membrane's unique properties allow for the separation of solid compounds and the degradation of organic materials through photocatalytic and antibacterial means. Poly(vinylidene fluoride)/titanium oxide (PVDF/TiO₂) composite remain the materials of choice for making these membranes due to their economy, effectiveness, safety, and durability. In this work a photocatalytic membrane reactor (PMR) system was developed using PVDF/TiO₂ membranes fabricated by the solution blow spinning (SBS) process. Obtaining photocatalytic membranes using this method is an efficient and ecological route that overcomes the disadvantage of separating the photocatalyst after the treatment is complete. The results of PMR system showed that the PVDF/TiO₂ membrane could effectively remove total coliforms and E. coli from polluted water. After 10 min of contaminated water circulation through the PMR system, the presence of pathogens was not detected, indicating the efficiency of the obtained membranes.     

ZnO/g-C3N4光催化剂在微流控芯片中的光催化性能

采用浸渍法合成ZnO质量分数不同的ZnO/g-C₃N₄复合光催化剂,分析样品的结构、形态、化学组成和光学性能等. 将制备好的样品固定到微流控芯片中,降解不同的染料（亚甲基蓝、中性红、孔雀石绿、罗丹明B）,评价样品在可见光下的光催化性能. 样品的表征结果表明,在ZnO/g-C₃N₄复合物中,ZnO、g-C₃N₄间存在相互作用,ZnO/g-C₃N₄复合物对可见光的利用更为充分;与g-C₃N₄相比,在ZnO/g-C₃N₄复合物中光生电子-空穴对的复合明显被抑制. 光催化实验结果表明,6 % ZnO/g-C₃N₄具有最佳光催化性能,在光照强度为60 klx,液体流速为20 μL/min时,其对罗丹明B溶液的降解效率为98.9%.多次循环后的光催化降解亚甲基蓝性能研究表明,样品在微流控芯片中进行光催化降解实验具有稳定性和可靠性.     

新型键联异质结CoMOF-g-C3N4-COOH用于可见光光解水产氢反应

基于钴金属有机骨架(CoMOF)和羧基化g-C₃N₄-COOH,设计合成了依靠化学键连接形成异质结界面的新型光催化剂CoMOF-g-C₃N₄-COOH。CoMOF-g-C₃N₄-COOH异质结材料具有优异的可见光下光解水制氢性能,产氢速率达到233 μmol/(g·h),与传统静电吸附合成的CoMOF-g-C₃N₄或纯g-C₃N₄-COOH相比,性能大幅提升。这是由于CoMOF/g-C₃N₄异质界面处化学键的设计构建,促进了光生载流子的传递,能够有效抑制电荷-空穴的复合。该工作证明了复合催化剂异质界面处成键对光生电子高效转移的作用,为设计高效光解水产氢的MOF基材料提供了新的思路。