银沉积纳米TiO2光催化剂的制备及活性

银沉积纳米TiO2光催化剂的制备及活性;纳米TiO2; 银沉积; 光催化; 甲基橙     

Synthesis and Crystal Structure of a Two-dimensional Silver Framework Constructed by H2idc (H2idc = Iminodiacetic Acid)

1 INTRODUCTION Self-assembly supramolecular architectures are currently of great interest due to their intriguing net- work topologies and potential applications in micro- electronics, nonlinear optics, porous materials, and other applications[1]. However, the rational design of these materials is complicated because of the un- certain coordination propensity of metal ion, which is influenced by factors such as counter ion, solvent and ligand geometry[2]. Proper selection of metal ions an…     

Three New Silver Alkylenediphosphonates with Pillar-like Open-frameworks

1 INTRODUCTION From 1970s many research interests have focused on metal organophosphonates due to their structural diversities, including layers[1, 2], zeolite-like[3], inor- ganic channel with organic shell[4], cage-like[5], homo- chiral framework[6] and ring-[7] or sphere-like[8] clus- ters, as well as their potential or practical applica- tions as Langmuir-Blodgett Film (LB)[9], meso/mi- cro-porous materials[10, 11], ion-exchangers [12], small molecular sensors[13], adsorptions/desorp…     

Quantum Chemistry Calculation of Quercetin-silver Complex

1 INTRODUCTION Quercetin(3,5,7,3?,4?-pentahydroxyflavone,see Fig. 1) is a kind of flavonol with many pharma-colo- gical actions, such as anti-flammatory, antiviral and antioxidation[1], but its antioxidation is weak. In re- cent years, it has been reported that quercetin can form metallic complexes by combining with some metal ions like copper ion, zinc ion, nickel and rare earth metals, and its antioxidative activity will be stronger than quercetin due to the existence of co- operative ef…     

银纳米棱镜的形成及其光学性能研究

以有机溶剂作为反应介质,聚合物为稳定剂,通过微波辅助溶液法成功地制备了具有特殊光学性能的银纳米棱镜.利用X射线衍射、透射电子显微镜和紫外-可见光谱等手段跟踪反应过程.结果显示,随着反应的进行,银纳米粒子由10nm左右的球形颗粒逐渐转变为具有规则三角形(或缺角的三角形)形貌的纳米棱镜;同时,紫外-可见吸收峰不但显示出明显的量子尺寸效应,而且吸收峰也由单一的等离子共振吸收峰变为多重的多极吸收峰共同存在,胶体溶液也随之显示出不同的颜色.改变反应物的配比、体系的浓度及无机前驱物都会得到位置和峰形各不相同的吸收曲线,从而得到多彩的纳米银胶体溶液.     

Preparation,Characterization and Optical Properties of Hostguest Nanocomposite Material Mordenite—silver Iodide

Silver iodide nanoclusters were successfully prepared in the channels of mordenite by a heat diffusion method.Powder X-ray diffraction.adsorption technique and infrared spectroscopy were used to characterize the prepared materials,which showed that the guest silver iodied had been encapsulated in the channels of mordenite.The optical properties of the solid phase diffuse reflectance absorption of nanocomposite material NaM-AgI were studied,showing that the absorption bands of the diffuse reflectance absorption of the prepared material moved to the region of high energy.The absorption peak of the material prepared shifted to the region of high energy.Namely,blue shift was caused.This has demonstrated the incorporation of silver iodide into the channels of the zeolite.We observed the luminescence and surface photovoltage spectra of NaM-AgI sample,proposing the mechanisms of the photoluminescence and photovoltaic responses.     

Thermodynamic Foundation for High Temperature Electrochemistry

Thermodynamic concepts required for the thermodynamic calculation of the potentials of electrodes for high temperature applications are briefly reviewed. A thermodynamic approach to the calculation of half cell potentials and the standard chemical potential of an electron at high temperatures which are related to the Standard Hydrogen Electrode(SHE) is discussed. As examples, an external Ag/AgCl reference electrode and a YSZ(Ag|O2) pH sensor for high temperature applications are analyzed by using the thermodynamic ap-proach to derive a high temperature pH measurement equation. The two electrodes are employed to measure high temperature pH and the measured pH was compared with the calculated pH by using a solution chem-istry method. Concepts and principles for electrode kinetics are also briefly introduced and a modification to the Tafel equations is suggested.     

皖南西坑Ag-Pb-Zn矿床稀土元素地球化学研究

对比研究了皖南西坑银多金属矿床中赋矿围岩蓝田组地层、成矿有关的花岗岩、矿石、矿床蚀变岩等地质体的稀土元素地球化学特征 ,借以示踪成矿物质来源。结果表明 ,西坑银多金属矿床成矿热液、成矿物质主要来源于花岗岩浆作用 ,成矿热液和富碳酸盐岩地层水岩反应使蚀变岩相对富集重稀土。     

乳酸杆菌A09吸附还原Ag(I)的谱学表征

Pooley[1]发现氧化亚铁硫杆菌(Thiobacillus ferroxidans)和氧化硫硫杆菌(Thiobacillus thiooxidans)能在其细胞表面累积银,形成Ag2S,每克干重细胞吸附250 mg Ag2S.文献[2]也报导了类似的研究结果.一些霉菌也具有吸收金、银等重金属的能力[3].Brierley等[4]研究了用微生物制备回收贵金属的去除剂(MRA),用它能从摄影废液中回收银,每克MRA累积94 mg Ag;同时指出,贵金属生物吸附也包含金属离子被还原为金属的过程.     

溶剂热法制备Ag/TiO2纳米材料及其光催化性能

以乙醇为溶剂, 钛酸四丁酯为前驱体, 用溶剂热法制备了Ag表面修饰的负载型纳米二氧化钛光催化剂. 利用X射线衍射(XRD)、N₂吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外-可见(UV-Vis)光谱等技术对其进行了系统的表征, 以亚甲基蓝(MB)溶液的脱色降解为模型反应, 考察了不同Ag含量样品的光催化性能. 结果表明: 用溶剂热法制备的样品中TiO₂皆为锐钛矿相, 金属Ag颗粒沉积在TiO₂表面, 粒径为2 nm左右, 比表面积较溶胶凝胶法制备的样品大大增加, 最高可达151.44 m²·g^-1; UV-Vis光谱和光催化实验表明: Ag修饰使TiO₂对光的吸收能力大大增强, 吸收带边红移至可见光区, 亚甲基蓝在该复合材料上的光催化降解反应遵循一级反应动力学模型; 溶剂热法制备样品的光催化性能明显好于溶胶凝胶法制备的样品, 在紫外光和可见光下, Ag摩尔分数为5%的样品表现出最佳的光催化活性.