Ln掺杂BiVO4(Ln=Eu、Gd、Er)光催化剂的制备和活性研究

采用水热合成法, 制备出Eu、Gd和Er掺杂的BiVO₄复合光催化剂,并采用X射线衍射、X射线光电子谱、扫描电子显微镜和紫外-可见漫反射光谱技术对其进行分析表征。通过可见光下降解水溶液中甲基橙分子来考察其光催化性能,结果显示掺杂的复合光催化剂活性都强于纯的BiVO₄,对掺杂复合光催化剂的催化活性增强机理进行了讨论和描述。     

Design of Advanced Functional Materials Using Nanoporous Single‐Site Photocatalysts

Nanoporous silica solids can offer opportunities for hosting photocatalytic components such as various tetra‐coordinated transition metal ions to form systems referred to as “single‐site photocatalysts”. Under UV/visible‐light irradiation, they form charge transfer excited states, which exhibit a localized charge separation and thus behave differently from those of bulk semiconductor photocatalysts exemplified by TiO₂. This account presents an overview of the design of advanced functional materials based on the unique photo‐excited mechanisms of single‐site photocatalysts. Firstly, the incorporation of single‐site photocatalysts within transparent porous silica films will be introduced, which exhibit not only unique photocatalytic properties, but also high surface hydrophilicity with self‐cleaning and antifogging applications. Secondary, photo‐assisted deposition (PAD) of metal precursors on single‐site photocatalysts opens up a new route to prepare nanoparticles. Thirdly, visible light sensitive photocatalysts with single and/or binary oxides moieties can be prepared so as to use solar light, the ideal energy source.     

特定结构光催化剂的制备及其构效关系

高效光催化剂的设计是光催化研究的关键.本文介绍了超临界处理、醇解、溶剂蒸发诱导自组装(EISA)法和喷雾干燥技术在特定结构TiO2和非钛催化剂制备中的应用,并初步介绍了光催化剂的构效关系,说明具有特定组成和形貌结构的光催化剂的制备对提高光催化性能起到了关键的作用.     

碳材料修饰铋系光催化剂及其应用

可见光半导体光催化剂具有高效利用太阳能从而解决能源及环境问题的优势,引起光催化及其他领域人们的关注.铋系光催化剂多属于窄带隙半导体材料,能够吸收太阳光谱中的大量可见光.此外,铋系光催化剂独特的层状晶体结构及较深的价带位置决定了其具有较高的催化活性,成为近年来半导体光催化领域研究的热点.碳基质材料由于具有比表面积大、热和化学稳定性高以及导电能力强等物理化学性质而被人们广泛研究.将碳材料与铋系半导体进行复合,两者之间的协同效应能够增强对反应物的吸附量,拓宽对太阳光的吸收范围,加速电子/空穴对的分离,从而提高催化活性.此外,碳材料修饰的铋光催化剂更易被分离及回收利用,可有效降低应用成本,具有潜在的应用前景.本文对近年来利用碳基质材料修饰铋系光催化剂的类型、制备方法、结构与性能、作用机理及其应用研究进行了综述,提出了目前利用碳材料修饰铋系光催化剂在材料设计、机理研究及应用等方面存在的主要问题,并对其未来发展方向进行了展望.     

Applications of Single-site Photocatalysts to the Design of Unique Surface Functional Materials

The isolated and tetrahedrally coordinated metal oxide (Ti, V, Cr, Mo and W-oxides) moieties can be included in the silica matrixes of silica-based microporous zeolite and mesoporous silica materials and named as “single-site photocatalysts”. Under UV-light irradiation these single-site photocatalysts form the charge transfer excited state, i.e., the excited electron–hole pair state which is located quite near to each other in different from the manner observed on semiconducting materials such as TiO₂, and play a significant role in various photocatalytic reactions. These single-site photocatalysts not only can promote photocatalytic reactions but also can be utilized to synthesis of functional materials. The nano-sized metal catalyst and visible-light sensitive binary oxide photocatalyst can be synthesized on the excited single-site photocatalyst under UV-light irradiation. The transparent mesoporous silica thin film with single-site photocatalyst generates the super-hydrophilic surface. In this review, our recent applications of single-site photocatalysts to synthesis of the surface functional materials have been introduced.     

可见光催化需氧氧化在有机合成中的应用

可见光催化作为一种新兴且强大的有机合成手段,具有洁净节能、优秀的官能团兼容性和良好的化学选择性等特征。氧气作为一种廉价、无污染的氧化剂,与可见光催化相结合,极大地促进了绿色化学的发展。本文主要对我们课题组近年来在可见光需氧氧化领域取得的成果做了简明的综述,并对其发展进行了展望。     

Magnetic retrievable Ag/AgBr/ZnFe2O4 photocatalyst for efficient removal of organic pollutant under visible light

In the present work, a visible-light-driven Ag/AgBr/ZnFe₂O₄ photocatalyst has been successfully synthesized via a deposition–precipitation and photoreduction method. The crystal structure, chemical composition, morphology and optical properties of the as-prepared nanocomposites were characterized by X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscope, UV–vis diffuse reflectance spectroscopy and photoluminescence. The photocatalytic activities of the Ag/AgBr/ZnFe₂O₄ nanocomposites were evaluated through the photodegradation of gaseous toluene and methyl orange (MO) under visible light. The results revealed that the as-prepared Ag/AgBr/ZnFe₂O₄ nanocomposite exhibited excellent photocatalytic activity. The degrading efficiency of MO could still reach 90% after four cycles, and the Ag/AgBr/ZnFe₂O₄ nanocomposite could be recycled easily by a magnet. Additionally, the enhanced photocatalytic mechanism was discussed according to the trapping experiments, which indicated that the photo-generated holes (h⁺) and •O₂⁻ played important roles in photodegradation process. At last, a possible photocatalytic oxidation pathways of toluene was proposed based on the results of GC–MS. The Ag/AgBr/ZnFe₂O₄ composites showed potential application for efficient removal of organic pollutant.     

化学修饰法制备光敏性壳聚糖胶束及其光响应特性

首先通过在壳聚糖氨基上键合环氧丙醇,得到具有良好水溶性与油溶性的缩水甘油壳聚糖(GC),然后用琥珀酰化7-二乙基氨基-4-羟甲基香豆素作为光敏剂修饰GC制得壳聚糖衍生物SCGC,它具有光触发解组装性能。采用FT-IR与1 H-NMR对所得壳聚糖衍生物(SCGC)的结构进行表征,通过跟踪胶束在紫外光照下粒径与Zeta电位的变化研究SCGC的光敏性。结果表明:SCGC具有预期的化学结构,在水中可组装成胶束,芘荧光探针法测得胶束的临界聚集浓度(CAC)为0.07mg/mL。随光照时间的延长,SCGC胶束粒径不断增大,胶束表面负电性也随之增强。     

Synthesis and Biological Activity Evaluation of Coumarin-3-Carboxamide Derivatives

A series of novel coumarin-3-carboxamide derivatives were designed and synthesized to evaluate their biological activities. The compounds showed little to no activity against gram-positive and gram-negative bacteria but specifically showed potential to inhibit the growth of cancer cells. In particular, among the tested compounds, 4-fluoro and 2,5-difluoro benzamide derivatives (14b and 14e, respectively) were found to be the most potent derivatives against HepG2 cancer cell lines (IC₅₀ = 2.62–4.85 μM) and HeLa cancer cell lines (IC₅₀ = 0.39–0.75 μM). The activities of these two compounds were comparable to that of the positive control doxorubicin; especially, 4-flurobenzamide derivative (14b) exhibited low cytotoxic activity against LLC-MK2 normal cell lines, with IC₅₀ more than 100 μM. The molecular docking study of the synthesized compounds revealed the binding to the active site of the CK2 enzyme, indicating that the presence of the benzamide functionality is an important feature for anticancer activity.     

Design,Synthesis, Spectroscopic Characterisation and In Vitro Cytostatic Evaluation of Novel Bis(coumarin-1,2,3-triazolyl)benzenes and Hybrid Coumarin-1,2,3-triazolyl-aryl Derivatives

In this work, a series of novel 1,2,3-triazolyl-coumarin hybrid systems were designed as potential antitumour agents. The structural modification of the coumarin ring was carried out by Cu(I)-catalysed Huisgen 1,3-dipolar cycloaddition of 7-azido-4-methylcoumarin and terminal aromatic alkynes to obtain 1,4-disubstituted 1,2,3-triazolyl-coumarin conjugates 2a–g, bis(1,2,3-triazolyl-coumarin)benzenes 2h–i and coumarin-1,2,3-triazolyl-benzazole hybrids 4a–b. The newly synthesised hybrid molecules were investigated for in vitro antitumour activity against five human cancer cell lines, colon carcinoma HCT116, breast carcinoma MCF-7, lung carcinoma H 460, human T-lymphocyte cells CEM, cervix carcinoma cells HeLa, as well as human dermal microvascular endothelial cells (HMEC-1). Most of these compounds showed moderate to pronounced cytotoxic activity, especially towards MCF-7 cell lines with IC₅₀ = 0.3–32 μM. In addition, compounds 2a–i and 4a–b were studied by UV-Vis absorption and fluorescence spectroscopy and their basic photophysical parameters were determined.     

La掺杂TiO2光催化剂的制备与表征

用共沉淀法和溶胶-凝胶法制备了La掺杂TiO2光催化剂(La3 -TiO2),并以罗丹明B为模型反应物,进行了光催化降解实验.结果发现,共沉淀法制备的La3 -TiO2具有较高的光催化活性,当掺La量为1.0%、于800℃煅烧2 h时获得的催化剂活性最佳.用X射线衍射、N2吸附、扫描电镜和电子探针等手段测定了两种方法制备的典型样品的结构和粒度分布.两种方法制备的催化剂都是含有锐钛矿和金红石型TiO2的混合晶体,但共沉淀法制备的催化剂具有较高的锐钛矿含量、较大的晶粒和大孔/介孔的多级孔结构,这是其具有较高光催化活性的主要原因.     

遗传算法及其在化学化工中的应用

本文介绍了遗传算法的基本概念、工作原理和步骤, 综述了它在化学化工领域的应用。     

人造细胞的化学构建及其生物医学应用研究

人造细胞是模拟生物细胞结构,人工构建的与细胞功能相近的微米囊泡。人造细胞的构建主要有两种模式：自上而下模式主要利用生物学方法对生物基因序列进行重新设计,获得具有细胞类似结构功能的人造细胞;自下而上模式主要利用化学方法采用非生命物质构筑简化的细胞结构模型。自下而上化学模式构建的人造细胞大多只包含执行所需功能的最小单元,具有简单的细胞仿生的结构与功能。本文详细综述了人造细胞的构建模式以及化学构建人造细胞的常见类型,包括脂质囊泡、蛋白体囊泡、聚合物囊泡、凝集体液滴和胶体囊泡等,总结了人造细胞在分析传感、细胞结构与功能模拟、生物载体转运、微纳米反应器、疾病诊疗方面的生物医学应用现状。     

深入理解化学平衡常数及其应用——对2019年全国理综(Ⅰ卷)化学第28题的分析

在已有的化学平衡常数教学的基础上,提出认知化学平衡常数的新角度--化学平衡常数的多种表达式。依据教材中用浓度表示的化学平衡常数并结合理想气体状态方程,推导用物质的量分数及分压表示的化学平衡常数表达式,分析3者之间的区别和联系,进而应用化学平衡常数的多种表达形式解决2019年全国(Ⅰ卷)化学第28题中的相关问题,使学生深入理解解答这道高考试题的关键所在。同时,拓展了学生对平衡常数的认识,提升了学生灵活应用平衡常数解决问题的能力。     

烯烃的交叉复分解反应(CM)及其合成应用

概述了近年来烯烃交叉复分解反应的研究进展及其在有机中间体制备、碳水化合物的合成、高分子化学以及工业生产上的应用.     

超临界甲醇在化学反应中的应用

超临界流体技术在绿色化工过程中的应用范围不断拓宽。由于超临界甲醇具有独特的物理和化学性质,它既是反应介质,也是反应物,因此,超临界甲醇下的化学反应研究得到人们广泛的关注。本文在介绍超临界甲醇独特的物理化学特性的基础上,综述了近年来超临界甲醇体系在有机合成、生物柴油的制备、生物质处理和高聚物的降解等方面的应用研究进展,重点对超临界甲醇下各种反应的影响因素进行了分析讨论。最后,展望了超临界甲醇在甲醇化工中的应用前景。     

Homocoupling Reactions of Azoles and Their Applications in Coordination Chemistry

Pyrazole, a member of the structural class of azoles, exhibits molecular properties of interest in pharmaceuticals and materials chemistry, owing to the two adjacent nitrogen atoms in the five-membered ring system. The weakly basic nitrogen atoms of deprotonated pyrazoles have been applied in coordination chemistry, particularly to access coordination polymers and metal-organic frameworks, and homocoupling reactions can in principle provide facile access to bipyrazole ligands. In this context, we summarize recent advances in homocoupling reactions of pyrazoles and other types of azoles (imidazoles, triazoles and tetrazoles) to highlight the utility of homocoupling reactions in synthesizing symmetric bi-heteroaryl systems compared with traditional synthesis. Metal-free reactions and transition-metal catalyzed homocoupling reactions are discussed with reaction mechanisms in detail.     

Electrocatalytic Organic-Inorganic Hybrid Films and Their Applications in Chemical Sensors and Biosensors

In this report, we will present the organic-inorganic hybrid molecular films prepared in our group and their applications in chemical sensors and biosensors.Many types of multi-layered films have been prepared in an alternatively assembled organic-inorganic and layer-by-layer manner. We will focus on the alternatively organized organic surfactant and metal-complex films and their conversion into electrocatalytically active films. Especially, we will demonstrate the preparation of bifunctional films for the detection of two different but correlated species, such as nitric oxide and oxygen, in biomedia.     

共价有机骨架的合成及其在气体吸附存储方面的应用

共价有机骨架(COFs)是一种新型的纳米结构材料,由于其独特的性质而受到人们的广泛关注.COFs的结晶.度高,孔径可调,比表面积大,具有良好的抗氧化性能和独特的分子结构,在能源、环境等方面得到了广泛的应用.COFs材料有较高的应用价值,促使人们不断努力研究其基本性质,并调控其结构和功能来提高性能.通过COFs的可设计性...