Highly Efficient Simulated Solar Light-Driven Photocatalytic Degradation of 4-Nitrophenol over CdS/Carbon/MoSx Hybrids

Among the various organic pollutants and industrial chemicals, 4-nitrophenol has been one of the most monitored substances in aqueous environments, due to its enhanced solubility in such systems. This research reports for the first time the microwave-assisted synthesis of CdS/carbon/MoS_x hybrids and the subsequent utilization of such systems as photocatalysts for 4-nitrophenol degradation. The hybrids demonstrated a variable photocatalytic activity, by using a variety of organic substances as precursors for the solvothermal carbonization step. By using ascorbic acid as precursor, the corresponding ternary composite exhibited excellent photocatalytic activity, with the 4-nitrophenol concentration been almost quantitatively decayed within 45 min of irradiation. This could be ascribed due to the generation of a high population of heterojunctions as well as the chemical speciation of Mo-based nanostructures. Such ternary hybrids may be utilized as potential photocatalytic systems in processes, where removal of toxic water-soluble substances is the key issue.     

核壳型PS/CdS复合催化剂的制备及其光催化性能

以聚苯乙烯(PS)微球为模板,聚乙烯比咯烷酮为偶联剂,用超声化学法合成了核壳型PS/CdS纳米复合光催化剂(1),其结构,形貌和光催化性能经FT-IR,UV-Vis,XRD,SEM,TEM和EDS和表征。考察了反应时间(t)和物料比r[n(S2-)∶n(Cd2+)]对1rt形貌的影响。在最佳反应条件[Cd(Ac)228mmol,r=1.4,于室温超声反应3.0h]下制备的11.43.0具有明显的核壳结构,颗粒均匀呈球形,分散性好,平均粒径约320nm。11.43.0光催化罗丹明(RhB)降解反应结果表明,70min脱色率达到100%。     

Fructose 1,6‐Bisphosphate Trisodium Salt as A New Phosphorus Source for the Rapid Microwave Synthesis of Porous Calcium–Phosphate Microspheres and their Application in Drug Delivery

Calcium phosphates (CPs), as the major inorganic component of biological hard tissues, have been investigated for applications as biomaterials owing to their excellent biocompatibility. However, the traditional synthetic CPs are usually prepared from inorganic phosphorus and calcium sources. Herein, we report a new strategy for the synthesis of a variety of calcium–phosphate nanostructures, including porous amorphous calcium phosphate (ACP) microspheres, hydroxyapatite (HAP) nanorods, and ACP/HAP composite microspheres, by using fructose 1,6‐bisphosphate trisodium salt (FBP) as an organic phosphorus source in aqueous solution in a rapid microwave‐assisted hydrothermal reaction. The important role of FBP and the effect of the experimental conditions on the formation and evolution of the CPs nanostructures were investigated. The crystal phase and composition of the as‐prepared products were characterized by powder X‐ray diffraction (XRD), FTIR spectroscopy, and thermogravimetric (TGA) analysis and the morphologies of the products were characterized by SEM and TEM. This method is facile, rapid, surfactant‐free, and environmentally friendly. The as‐prepared porous ACP microspheres have a relatively high drug‐loading capacity and good sustained drug‐release behavior; thus, they are promising for applications in drug delivery.     

氧化石墨烯在仿生合成中的应用及研究

氧化石墨烯薄片的边缘含有大量的含氧功能团(如羧基等),这些官能团可以有效地与金属离子作用而成为晶体的成核位点,从而使得氧化石墨烯具备模板功能而用于仿生合成。论文综述了氧化石墨烯用作模板剂在仿生合成有机/无机杂化材料方面的应用研究进展,介绍了其基本原理,阐述了不同类型杂化材料的制备方法,并展望了石墨烯基有机/无机杂化材料的发展新趋势。     

微波辅助合成石墨烯/氧化镍复合材料及其表征

本文通过微波辅助的方法,快速而有效地在热膨胀石墨烯(RG)的缺陷上原位合成氧化镍纳米颗粒,形成石墨烯/氧化镍复合材料(RG/NiO)。利用X-射线衍射(XRD),拉曼光谱(Raman),傅里叶变换红外(FTIR),扫描电镜(SEM),透射电镜(TEM),热重-差热(TGA-DSC)对所制备样品的结构、形貌和NiO在复合材料中的含量进行表征。结果表明,热膨胀石墨烯层数约7~8层,层间距约为0.35 nm,缺陷多,在水热和微波处理后抗氧化性明显变差。复合材料中氧化镍颗粒平均粒径为25 nm,均匀而密集地分散在石墨烯平面上,同时在复合材料中的含量为19.8%。     

微波辅助合成石墨烯/氧化镍复合材料及其表征

本文通过微波辅助的方法,快速而有效地在热膨胀石墨烯(RG)的缺陷上原位合成氧化镍纳米颗粒,形成石墨烯/氧化镍复合材料(RG/NiO)。利用X-射线衍射(XRD),拉曼光谱(Raman),傅里叶变换红外(FTIR),扫描电镜(SEM),透射电镜(TEM),热重-差热(TGA-DSC)对所制备样品的结构、形貌和NiO含量在复合材料中的含量进行表征。结果表明,热膨胀石墨烯层数约7~8层,层间距约为0.35nm,缺陷多,在水热和微波处理后抗氧化性明显变差。复合材料中氧化镍颗粒平均粒径为25nm,均匀而密集地分散在石墨烯平面上,同时在复合材料中的含量为19.8%。     

自组装合成纳米复合TiO2-ZnO介孔材料及其光催化性能

以TiCl₄, ZnSO₄•7H₂O为原料, 尿素为沉淀剂, 利用可溶性淀粉大分子链的空间位阻效应和高分子网络的阻隔作用, 以纳米级碳黑为模板, 采用微波加热、均相沉淀法合成出了一系列纳米TiO₂-ZnO复合介孔材料. XRD分析证明反应前驱体为非晶态, 500 ℃以上转变为锐钛矿结构的TiO₂和ZnTiO₃, 当Ti∶Zn＝1(摩尔比)时, 产物全部为ZnTiO₃ (TiO₂•ZnO). TEM形貌观察结合N₂吸附表明, 基本粒子为球形, 粒径15～20 nm. 最可几孔径8～10 nm. EDS分析证明产品中Ti∶Zn的分析测定值与实际的投料值基本一致, 并且掺杂均匀性好. 光吸收及光催化实验发现Zn含量为50%时, 光催化效果最好, 在日光照射90 min后, 此TiO₂-ZnO复合材料对藏蓝染料溶液降解率可达到100%, 其光催化反应符合一级动力学方程.     

微波固相剥离法制备功能化石墨烯及其电化学电容性能研究(英文)

通过微波固相剥离氧化石墨制备了功能化石墨烯材料。石墨烯的剥离,是由于微波加热过程中氧化石墨烯片上的官能团分解为CO2和H2O,产生的压力超过了片层间的范德华力。形貌表征显示了石墨烯的有效剥离和纳米孔结构的形成。红外光谱分析结果表明微波剥离的功能化石墨烯仍然有少量的官能团残留。N2等温吸附-脱附测试结果表明样品具有高比表面积(412.9m2·g-1)和大孔容(1.91cm3·g-1)。电化学测试结果表明功能化石墨烯具有良好的电化学电容行为和207.5F·g-1的比电容。     

Microwave‐Induced In Situ Synthesis of Zn2GeO4/N‐Doped Graphene Nanocomposites and Their Lithium‐Storage Properties

Zn₂GeO₄/N‐doped graphene nanocomposites have been synthesized through a fast microwave‐assisted route on a large scale. The resulting nanohybrids are comprised of Zn₂GeO₄ nanorods that are well‐embedded in N‐doped graphene sheets by in situ reducing and doping. Importantly, the N‐doped graphene sheets serve as elastic networks to disperse and electrically wire together the Zn₂GeO₄ nanorods, thereby effectively relieving the volume‐expansion/contraction and aggregation of the nanoparticles during charge and discharge processes. We demonstrate that an electrode that is made of the as‐formed Zn₂GeO₄/N‐doped graphene nanocomposite exhibits high capacity (1463 mAh g^?1 at a current density of 100 mA g^?1), good cyclability, and excellent rate capability (531 mAh g^?1 at a current density of 3200 mA g^?1). Its superior lithium‐storage performance could be related to a synergistic effect of the unique nanostructured hybrid, in which the Zn₂GeO₄ nanorods are well‐stabilized by the high electronic conduction and flexibility of N‐doped graphene sheets. This work offers an effective strategy for the fabrication of functionalized ternary‐oxide‐based composites as high‐performance electrode materials that involve structural conversion and transformation.     

可磁分离的镍锌铁氧体-石墨烯复合材料的制备及其光催化性能

以硝酸锌、硝酸镍、硝酸铁为原料,采用微波水热法快速制备了Ni_0.5Zn_0.5Fe₂O₄-graphene纳米复合材料。该复合材料的XRD、Raman、TEM/HRTEM、XPS和VSM结果表明13 nm左右的尖晶石型镍锌铁氧体纳米颗粒分散锚固在石墨烯片上,纳米复合材料的饱和磁化强度为28.2 A·m²·kg^-1,剩磁和矫顽力基本为零表现为超顺磁性。在H₂O₂存在条件下可见光照射90 min,亚甲基蓝(MB)降解率达到97.5%,较好的光催化活性主要归因于石墨烯的存在有利于光生载流子的分离,产生更多活性中间体用于有机染料污染物的降解。考察了磁性光催化剂的重复利用和催化能力的稳定性,能够满足磁性回收和再使用的要求。     

石墨烯气凝胶吸附剂的制备及其在水处理中的应用

石墨烯气凝胶(GA)是以石墨烯为主体的三维互联的多孔网络结构,因其具有优良的结构可控性、极大的比表面积、独特的空间互联结构、良好的电子传输能力成为水处理中应用的理想材料。至今已经有大量制备GA的方法,其性能和结构因制备方法的不同差异很大,但是尚未有文献系统地报道GA的制备机理和不同方法与GA结构及性能之间的联系。本文系统性地介绍GA吸附剂的制备方法与它在水处理中的应用并进行展望。对GA的结构特性尤其是与吸附有关的特性以及结构和吸附之间的关系进行分析,并通过对GA的制备机理和制备过程中的关键因素进行归纳,基于GA的制备机理将其制备方法进行分类(模板法、垫片支撑法、自支撑法、基面法和凝胶法)并对五种方法进行了详细介绍,对目前GA在水处理技术中(吸附、光催化、去离子电容等)去除重金属和有机污染物相关应用和机理进行综述,最后对目前GA在环境中应用中存在的问题及研究前景进行了总结和展望。     

可磁分离的镍锌铁氧体-石墨烯复合材料的制备及其光催化性能

以硝酸锌、硝酸镍、硝酸铁为原料,采用微波水热法快速制备了Ni_(0.5)Zn_(0.5)Fe_2O_4-graphene纳米复合材料。该复合材料的XRD、Raman、TEM/HRTEM、XPS和VSM结果表明13 nm左右的尖晶石型镍锌铁氧体纳米颗粒分散锚固在石墨烯片上,纳米复合材料的饱和磁化强度为28.2 A·m~2·kg~(-1),剩磁和矫顽力基本为零表现为超顺磁性。在H_2O_2存在条件下可见光照射90 min,亚甲基蓝(MB)降解率达到97.5%,较好的光催化活性主要归因于石墨烯的存在有利于光生载流子的分离,产生更多活性中间体用于有机染料污染物的降解。考察了磁性光催化剂的重复利用和催化能力的稳定性,能够满足磁性回收和再使用的要求。     

Ag负载TiO2纳米管微波辅助水热法制备及其光催化性能

以微波辅助水热法制备了二氧化钛纳米管,然后通过浸渍法在其表面负载了银纳米颗粒.所得样品用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、氮吸附、X射线光电子能谱(XPS)、紫外-可见漫反射等测试方法表征.微波加热处理可以大大缩短反应时间,产物为无定型纳米管,经高温焙烧后转变成锐钛矿型二氧化钛.所得纳米管的外径为7-8 nm,内径为5-6 nm,管长约200 nm,比表面积可达371 m2·g-1.负载的银分散在纳米管的表面,对纳米管的结构与晶型没有影响,但是拓宽了二氧化钛的光吸收范围,使吸收边红移至可见光区,并且有效抑制了光生电子空穴的复合.在可见光降解罗丹明B的实验过程中,与Ag负载的P25及纯二氧化钛纳米管相比,Ag负载二氧化钛纳米管具有更高的可见光催化活性,并且当Ag/Ti 物质的量的比为0.5%时,可见光催化性能最好.     

Hydrothermal Deoxygenation of Graphene Oxide: Chemical and Structural Evolution

A green and facile approach for the partial deoxygenation of graphene oxide (GO) at moderate temperature (100 °C) and under atmospheric pressure, catalyzed by acidic conditions in water is reported. The chemical and structural changes in GO as a function of hydrothermal time were probed to understand the deoxygenation events. The brown GO dispersion in water was found to gradually turn black over the hydrothermal‐treatment time on account of the increasing graphitic content. FTIR, thermogravimetric (TG), Raman, and XRD analyses revealed that the labile oxygen functionalities are progressively eliminated, thereby partially restoring the π‐conjugated network. This was further corroborated by X‐ray photoelectron spectroscopy (XPS) studies based on quantitative analysis of each carbon component associated with the different chemical functionalities. Carbonyl, carboxyl, ether, and phenolic groups were found to be thermally stable, which hinders complete deoxygenation of GO and makes their dispersion in water stable, as monitored by the ζ potential. It is worth noting that deoxygenation events are expedited under acid‐catalyzed hydrothermal treatment relative to thermal deoxygenation in air.     

Green and Rapid Hydrothermal Crystallization and Synthesis of Fully Conjugated Aromatic Compounds

Highly fused, fully conjugated aromatic compounds are interesting candidates for organic electronics. With higher crystallinity their electronic properties improve. It is shown here that the crystallization of three archetypes of such molecules—pentacenetetrone, indigo, and perinone—can be achieved hydrothermally. Given their molecular structure, this is a truly startling finding. In addition, it is demonstrated that perinone can also be synthesized in solely high‐temperature water from the starting compounds naphthalene bisanhydride and o‐phenylene diamine without the need for co‐solvents or catalysts. The transformation can be drastically accelerated by the application of microwave irradiation. This is the first report on the hydrothermal generation of two fused heterocycles.     

Facile Synthesis of Nitrogen‐Doped Graphene Aerogels for Electrode Materials in Supercapacitors

Three‐dimensional porous nitrogen‐doped graphene aerogels (NGAs ) were synthesized by using graphene oxide (GO ) and chitosan (CS ) via a self‐assembly process by one‐pot hydrothermal method. The morphology and structure of the as‐prepared materials were characterized by means of scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, XPS spectroscopy, Raman spectroscopy, nitrogen adsorption/desorption measurement and Fourier transform infrared spectroscopy. The electrochemical performance of NGAs was studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The microstructure, surface area and capacitance of NGAs could be facilely controlled by adding different amounts of chitosan. The prepared NGA ‐4 showed a specific capacitance of 148.0 F/g at the discharge current density of 0.5 A/g and also retained 95.3% of the initial capacitance after 5000 cycles at the scan rate of 10 mV /s. It provided a possible way to obtain graphene based materials with high surface area and capacitance.     

Hierarchical Hollow Hydroxyapatite Microspheres: Microwave‐Assisted Rapid Synthesis by Using Pyridoxal‐5′‐Phosphate as a Phosphorus Source and Application in Drug Delivery

Three‐dimensional (3D) hydroxyapatite (HAP) hierarchical nanostructures, in particular hollow nanostructures, have attracted much attention owing to their potential applications in many biomedical fields. Herein, we report a rapid microwave‐assisted hydrothermal synthesis of a variety of hydroxyapatite hierarchical nanostructures that are constructed by the self‐assembly of nanorods or nanosheets as the building blocks, including HAP nanorod‐assembled hierarchical hollow microspheres (HA‐NRHMs), HAP nanorod‐assembled hierarchical microspheres (HA‐NRMs), and HAP nanosheet‐assembled hierarchical microspheres (HA‐NSMs) by using biocompatible biomolecule pyridoxal‐5′‐phosphate (PLP) as a new organic phosphorus source. The PLP molecules hydrolyze to produce phosphate ions under microwave‐hydrothermal conditions, and the phosphate ions react with calcium ions to form HAP nanorods or nanosheets; then, these nanorods or nanosheets self‐assemble to form 3D HAP hierarchical nanostructures. The preparation method reported herein is time‐saving, with microwave heating times as short as 5 min. The HA‐NRHMs consist of HAP nanorods as the building units, with an average diameter of about 50 nm. The effects of the experimental conditions on the morphology and crystal phase of the products are investigated. The hydrolysis of PLP under microwave‐hydrothermal conditions and the important role of PLP in the formation of 3D HAP hierarchical nanostructures are investigated and a possible formation mechanism is proposed. The products are explored for potential applications in protein adsorption and drug delivery. Our experimental results indicate that the HA‐NRHMs have high drug/protein‐loading capacity and sustained drug‐release behavior. Thus, the as‐prepared HA‐NRHMs are promising for applications in drug delivery and protein adsorption.     

Nanostructured Graphene/TiO2 Hybrids as High‐Performance Anodes for Microbial Fuel Cells

A new nanostructured graphene/TiO₂ (G/TiO₂) hybrid was synthesized by a facile microwave‐assisted solvothermal process in which amorphous TiO₂ was assembled on graphene in situ. The resulting G/TiO₂ hybrids were characterized by XRD, SEM, TEM, Raman spectroscopy, and N₂ adsorption/desorption analysis. The electrochemical properties of the hybrids as anode materials for Shewanella‐inoculated microbial fuel cells (MFCs) were studied for the first time, and they proved to be effective in improving MFC performance. The significantly improved bacterial attachment and extracellular electron‐transfer efficiency could be attributed to the high specific surface area, active groups, large pore volume, and excellent conductivity of the nanostructured G/TiO₂ hybrid, and this suggests that it could be a promising candidate for high‐performance MFCs.     

Rapid and Convenient Thermal or Microwave-Assisted Synthesis of Substituted 2-Phenylbenzothiazoles

A simple one-step method for the synthesis of biologically relevant 2-phenylbenzothiazoles has been developed, using sodium metabisulfite as an oxidant following condensation between 2-aminothiophenol and substituted benzaldehydes. Attractive features of this new method include excellent yields under both microwave-assisted or thermal conditions (it is tolerant of a variety of substituents on the phenyl ring) and simple product isolation without the need for chromatographic purification.