水热法合成Ag_2CO_3/ZnO异质结复合光催化剂及其光催化性能

采用水热法合成了一系列不同Ag2CO3含量的新型Ag2CO3/ZnO异质结复合光催化剂,运用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、紫外-可见漫反射吸收光谱(UV-vis DRS)等系列手段对所制备的光催化剂进行了表征,并以紫外光(254 nm)为光源,评价了催化剂光催化降解甲基橙的活性,考察了不同Ag2CO3复合量、不同水热温度对ZnO复合光催化剂反应活性的影响.结果表明,当Ag2CO3含量为2%、水热温度为140℃,复合光催化剂具有最大的光催化活性,降解率达到86.31%.Ag2CO3/ZnO异质结复合光催化剂具有更高的光催化活性主要原因是复合光催化剂对紫外光有很强的吸收能力,适量Ag2CO3能提高光生电子-空穴对的分离效率,并改善催化剂的物理性能.     

水热法合成Ag2C03／ZnO异质结复合光催化剂及其光催化性能

采用水热法合成了一系列不同Ag2CO3含量的新型Ag2CO/ZnO异质结复合光催化剂,运用X射线粉末衍射（XRD）、扫描电镜（SEM）、X射线光电子能谱（XPS）、傅里叶变换红外光谱（FT-IR）、紫外-可见漫反射吸收光谱（UV-visDRS）等系列手段对所制备的光催化剂进行了表征,并以紫外光（254nm）为光源,评价了催化剂光催化降解甲基橙的活性,考察了不同Ag2CO3复合量、不同水热温度对ZnO复合光催化剂反应活性的影响．结果表明．当Ag2CO3含量为2％、水热温度为140℃,复合光催化剂具有最大的光催化活性,降解率达到86．31％．Ag2CO3/ZnO异质结复合光催化剂具有更高的光催化活性主要原因是复合光催化剂对紫外光有很强的吸收能力,适量A龅C03能提高光生电子一空穴对的分离效率,并改善催化剂的物理性能．     

稀土复合氧化物燃烧催化剂的性能及表征

浸渍法制备了稀土型燃烧催化剂 ,采用多晶 X射线衍射 (XRD)、程序升温还原 (TPR)、差热热重分析(DTA- TG)、X射线光电子能谱 (XPS)和二甲苯催化氧化活性测试等方法表征了该燃烧催化剂的结构和性能     

水热法合成Ag2CO3/ZnO异质结复合光催化剂及其光催化性能

采用水热法合成了一系列不同Ag₂CO₃含量的新型Ag₂CO₃/ZnO异质结复合光催化剂, 运用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、紫外-可见漫反射吸收光谱(UV-vis DRS)等系列手段对所制备的光催化剂进行了表征, 并以紫外光(254 nm)为光源, 评价了催化剂光催化降解甲基橙的活性, 考察了不同Ag₂CO₃复合量、不同水热温度对ZnO复合光催化剂反应活性的影响.结果表明, 当Ag₂CO₃含量为2 %、水热温度为140 ℃, 复合光催化剂具有最大的光催化活性, 降解率达到86.31 %.Ag₂CO₃/ZnO异质结复合光催化剂具有更高的光催化活性主要原因是复合光催化剂对紫外光有很强的吸收能力, 适量Ag₂CO₃能提高光生电子-空穴对的分离效率, 并改善催化剂的物理性能.      

制备工艺对LaMnO3钙钛矿型催化剂性能影响的研究

采用共沉淀法、溶胶-凝胶法和燃烧法制备LaMnO3钙钛矿型催化材料,考察了不同制备方法对催化材料结构和性能的影响.用X射线衍射仪(XRD)、比表面测定仪(BET)和扫描电子显微镜(SEM)等分析手段对催化剂的微观结构进行了表征.用催化剂评价系统考察了催化剂对CO的催化氧化活性.     

负载型纳米金催化剂的合成、表征及性能研究

以SiO2和纳米Au颗粒为原料,采用自组装方法合成了负载型金催化剂。应用傅立叶变换红外光谱(FT-IR)、X射线能谱(EDS)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)及原子吸收光谱(AAS)等对样品进行了表征。将该催化剂用于空气氧化环己烷反应的实验结果显示,其不仅具有较高的催化活性和稳定性,而且经简单处理即可重复使用多次。     

可见光活性CdS-SiO2的制备及性能

用沉淀法制得CdS纳米粒子,用氨水催化分解正硅酸乙酯制得复合光催化剂CdS-SiO2。光还原沉积法对CdS表面载Pt。借助X射线衍射(XRD)、紫外-可见漫反射(UV-Vis)对催化剂进行表征,用电化学法测定CdS的光腐蚀度,以甲酸水溶液的可见光催化制氢反应为探针,评价催化剂活性。结果表明,SiO2的复合提高了CdS的分散性,抑制了CdS光腐蚀,从而使CdS的可见光制氢活性大大提高。     

电化学沉淀法净化含氰废水研究

含氰废水绿色、低成本处理制约着黄金氰化企业的可持续发展.以锌板为牺牲阳极,采用电化学沉淀法处理含氰废水,考察了电流密度、pH和初始总氰化合物浓度对氰化物去除效果的影响.结合循环伏安法、pHpzc、X射线衍射法、扫描电镜/能谱法和X射线光电子能谱法表征结果阐释氰化物去除机理.试验结果表明:在最佳条件下,工业含氰废水中总氰...     

氧化对含钛高炉渣钛组分走向的作用

 改变含钛高炉渣中矿相组成的研究是含钛高炉渣综合利用的关键;通过背散射电子形貌像、X射线能谱分析和X射线物相分析等手段,对氧化前的含钛高炉渣及其氧化改性后的渣样进行分析,表明氧化后渣中含钛相的形貌、成分和相结构等发生变化;钛的赋存状态也发生相应的改变。     

异质结光催化剂MWCNT/BiVO_4的合成及其光催化活性和稳定性研究

采用溶胶-凝胶法将多壁碳纳米管(MWCNT)和BiVO_4有效复合,制备出一系列不同掺杂量的异质结构复合光催化剂MWCNT/BiVO_4,通过X射线衍射(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)等对催化剂进行表征分析,以罗丹明B为目标污染物,考察了光催化活性和稳定性。结果表明,合成的复合光催化剂均为单斜相晶体结构,MWCNT的引入没有改变BiVO_4的主体物相,两者充分接触、结合形成了复合结构;MWCNT较强的电子俘获能力和大的比表面积增加了复合材料表面的活性位点,MWCNT,BiVO_4存在于MWCNT-BiVO_4复合体系中且都保持各自化合态;综合分析,MWCNT/BiVO_4形成的复合结构为异质结构,异质结构具有典型的提高量子效率的特点,能够有效抑制电子-空穴再复合现象的发生。当MWCNT的含量为2%(质量分数)时,催化剂的效果最好,实验条件下光降解罗丹明B的去除率高达84.08%,五次重复性实验之后,MWCNT/BiVO_4的降解率仍在80%左右。     

NiO-La2O3/γ-Al2O3催化剂中各组分间的相互作用

本文采用差热分析、X射线衍射、透射电镜和选区电子衍射对催化剂的物种情况及形貌加以研究 ,结合催化剂焙烧过程的相变情况 ,从而获得催化剂焙烧过程的化学反应情况。发现稀土助剂的加入使载体的晶体结构发生变化 ,从而使载体表面改性 ,抑制了 Ni Al2 O4的生成 ,提高了 Ni O的分散度。而且发现有 L a2 O2 CO3晶体存在于载体表面 ,L a2 O3以高度分散的状态存在     

Modified-EISA synthesis of mesoporous high surface area CeO_2 and catalytic property for CO oxidation

Mesoporous CeO2 particles with high surface area were synthesized using a modified evaporation-induced self assembly(EISA) method which combined citric acid as complexing agent.As-prepared powder and further thermal treatment samples were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),Fourier transform infrared spectrometer(FTIR),thermogravimetry and differential thermal analysis(TG-DTA),Brunauer-Emmett-Teller(BET) and Barrett-Joyner-Ha...     

Application of Sulfide Copper Ores Oxidizing Roasting Products as Sulfidizing Agent During Melting Nickel Raw Materials To Matte

Metallurgist - X-ray fluorescence analysis, X-ray powder diffraction, electron microprobe analysis, scanning electron microscopy, and thermal analysis are used to evaluate the material composition,...     

Mineralogical and Physical–Chemical Characterization of a Bauxite Ore from Lages,Santa Catarina,Brazil, for Refractory Production

Bauxite is widely used for refractory production owing to its high alumina content and high melting point. Brazil is one of the world's biggest producers of bauxite for refractory applications, and Santa Catarina State can be highlighted as one of the biggest reservoirs of bauxite ore. In spite of this fact, its chemical and mineralogical characteristics are not well known as well as its high temperature properties. The studied ore was completely characterized [chemical (X-ray fluroscence), thermal (differential thermal analysis), mineralogical (X-ray diffraction), and microscopic (optical microscopy and scanning electron microscopy) analyses] and the results showed that the bauxite ore is suitable to be used as a raw material for refractory applications.     

Synthesis of La3+ and Nd3+ co-doped yttria nanopowder for transparent ceramics by oxalate precipitation method

Polycrystalline Nd3+ and La3+ co-doped yttria nanopowder Nd3+:Y1.90La0.10O3 for transparent ceramics was synthesized by co-precipitation method using oxalate acid as the precipitant and(NH4)2SO4 as the electrical stabilizer under ultrasonic radiation.Nanopowders calcined at different temperatures were characterized with thermal gravimetric-differential thermal analysis(TG/DTA),X-ray diffraction(XRD),transmitting electron microscopy(TEM),energy dispersive spectrometry(EDS) and spectral analysis techniques.Th...     

Structural developments in plastically deformed Ti-IF steel

X-ray diffraction peak profile analysis is a powerful and convenient method to investigate the microstructural characteristics of plastically deformed materials. The selection of a suitable and reliable analysis method is critical to derive correct microstructural/material property values. Different techniques of the X-ray diffraction peak profile analysis have been used to study the microstructural parameters of plastically deformed iron powder viz., coherent domain size, dislocation density and their nature. In particular, the classical and modified Williamson-Hall method and the momentum method are used. The nature (screw or edge) of dislocations is also determined for the deformed steel using X-ray diffraction while the morphology was studied using scanning electron microscopy.     

Influence of preparation method on performance of a metal supported perovskite catalyst for combustion of methane

A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane.The prepared metallic catalysts were characterized by means of X-ray diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and also by ultrasonic and thermal shock tests and catalytic activity.It was found that the process factors during the preparation,e.g.the preparation of the catalyst precursor and the coating slurry,the calcination te...     

Co-precipitation Synthesis and Spectroscopic Studies of YAG and Yb:YAG Nanopowder for Opto-Electronic Applications

Rare-earth doped YAG nanopowders are widely used as luminescence material because of its technological importance in opto-electronic applications especially for solid state lasers. In this work, YAG and Yb:YAG were prepared by co-precipitation method. The thermal behavior was investigated by differential thermal analysis and thermo gravimetric analysis. The phase formation, elemental analysis, particle size distribution, optical absorbance, fluorescence behavior and morphology of YAG and Yb:YAG nanopowder were analyzed through powder X-ray diffraction technique, energy dispersive X-ray analysis, dynamic light scattering, UV–Vis, photoluminescence spectroscopy, high resolution scanning electron microscopy, high resolution transmission electron spectroscopy respectively. From the optical study, Yb:YAG gives optical absorption at 975 nm and predominant infrared emission at 1030 nm.     

3种还原剂对锰氧化物结构和形貌的影响

锰氧化物的性能很大程度上受其形貌结构的影响。以高锰酸为氧化剂,乙酸锰、双氧水和硫酸锰为还原剂制备锰氧化物,对产物的结构、形貌和热稳定性分别用XRD、SEM、TEM和TG分析,讨论了不同还原剂对产物、结构、形貌和热稳定性的影响。