One-step solvothermal synthesis of N-doped TiO2 nanoparticles with high photocatalytic activity in the reduction of aqueous Cr（Ⅵ）

N-doped TiO2 （N-TiO2） nanoparticles were synthesized via a one-step low temperature （180℃） solvothermal route, which adopted NH4NO3 as the nitrogen source. The structure, composition, BET specific surface area, and optical properties of the as-synthesized product were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption- desorption isotherms, and UV-vis diffuse reflectance spectroscopy. In addition, its photocatalytic properties were tested by the reduction of aqueous Cr（VI） under UV and visible light （x 〉 420 rim） irradiation. It was observed that for the reduction of aqueous Cr（VI）, the as-synthesized N-TiO2 nanoparticles not only exhibited much higher photocatalytic activity than P25 TiO2 under UV light, but also exhibited remarkably high photocatalytic activity under visible light （λ 〉 420 nm）.     

Separation of CO2/CH4 and CH4/N2 mixtures using MOF-5 and Cu3（BTC）2

In this paper we used MOF-5 and Cu3（BTC）2 to separate CO2/CH4 and CI-I4/N2 mixtures under dynamic conditions. Both materials were synthesized and pelletized, thus allowing for a meaningful characterization in view of process scale-up. The materials were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. By performing breakthrough experiments, we found that Cu3（BTC）2 separated CO2/CH4 slightly better than MOF-5. Because the crystal structure of Cu3 （BTC）2 includes unsaturated accessible metal sites formed via dehydration, it predominantly interacted with CO2 molecules and more easily captured them. Conversely, MOF-5 with a suitable pore size separated CH4/N2 more efficiently in our breakthrough test.     

Synthesis and photocatalytic properties of core–shell TiO~2@ZnIn_2S_4 photocatalyst

A novel core–shell TiO2@ZnIn2S4composite has been synthesized successfully by a simple and flexible hydrothermal route using TiO2as precursors.The as-synthesized samples were characterized by X-ray diffraction,UV–vis diffuse reflectance spectra and transmission electron microscopy.The photocatalytic properties of samples were tested by degradation of aqueous methylene blue（MB）under visible light irradiation.It was found that the as-synthesized TiO2@ZnIn2S4photocatalyst was more effcient than TiO2and ZnIn2S4in the photocatalytic degradation of MB.Moreover,TEM images confrmed the TiO2@ZnIn2S4nanoparticles possessed a well-proportioned core–shell morphology.     

由钛铁矿制备Fe3O4/TiO2复合物的研究进展

归纳了从钛铁矿中分离铁和二氧化钛的方法,包括亚熔盐法、预氧化法、还原锈蚀法;其次,初步总结了目前国内外制备Fe_3O_4磁性纳米颗粒和TiO_2纳米粒子的方法。最后,对Fe_3O_4/TiO_2复合材料的制备方法包括溶胶-凝胶法、微乳液法、均匀沉淀法作了梳理。Fe_3O_4/TiO_2复合纳米材料很好地解决了单独使用TiO_2作为废水处理催化剂,在实际应用过程中易随水流失,难以回收利用的问题,具有一定的实用性。     

Hydrothermal Synthesis of CdIn2S4 and Photocatalytic Degradation of Methyl Orange under Visible-light Irradiation

CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to characterize the products. It was found that the crystallographic structure and optical property of the products synthesized at different temperature were almost the same. The SBET of CdIn2S4 products decreased when the synthesized temperature increased, and the largest SBET was 33.16m2g-1 (120 ℃ sample). The degradation of methyl orange (MO) under the visible-light irradiation had been used as a probe reaction to investigate the photocatalytic activity of the as-prepared CdIn2S4, which showed that the CdIn2S4 sample synthesized at 120 ℃ presented the best photocatalytic activity for MO degradation.     

Synthesis of BiVO_4 nanosheets-graphene composites toward improved visible light photoactivity

Two-dimensional （2-D） BiVO4 nanosheets-graphene （GR） composites with different weight addition ratios of GR have been prepared via a facile wet chemistry process. X-ray diffraction （XRD）, Raman spectra, X-ray photoelectron spectra （XPS）, UV-vis diffuse reflectance spectra （DRS）, field-emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM）, nitrogen adsorption-desorption, transient photocurrent response and photoluminescence （PL） spectra were employed to determine the properties of the samples. It is found that BiVO4 nanosheets could pave well on the surface of graphene sheets. BiVO4 nanosheets-GR composites with a proper addition amount of GR exhibited higher photocatalytic activity than bare BiVO4 nanosheets toward liquid-phase degradation of rhodamine B （RhB） and methyl orange （MO） under visible light irradiation. The enhancement of photocatalytic activities of BiVO4 nanosheets-GR composites can be attributed to the effective separation of photoexcited electron-hole pairs. This work not only provides a simple strategy for fabricating specific 2-D semiconductor-2-D GR composites, but also opens a new window of such 2-D semiconductor-2-D GR composites as visible light photocatalysts toward an improved visible light photoactivity in purifying polluted water resources.     

硫化态NiW／AI2O3催化剂加氢脱硫活性相的研究 I．XPS和HREM表征

采用孔饱和共浸法制备了一系列具有相同W含量和不同Ni含量的NiW／AI2O3催化剂，并对相应的硫化态催化剂进行了XPS和HREM表征．结果表明，引入的助剂Ni优先修饰WS2晶粒的边角位置，形成高活性的NiWS相．催化剂中助剂Ni在噻吩加氢脱硫反应中的显著促进效应(活性提高了约30倍)与形成的NiWS活性相数量有关．同时，助剂Ni的引入使得催化剂表面WS2晶粒的堆叠程度略有增加，晶片长度略有减小；而且引入助剂后WO，相的硫化度提高了近20％．但相比之下，活性相织构的变化和硫化度的增大对催化脱硫活性的贡献较小，不是Ni产生助剂效应的主要原因．     

磁性纳米TiO2/Fe3O4光催化复合材料的制备及性能

采用溶胶-凝胶法，在磁性Fe3O4表面包覆TiO2，制备了一种新型纳米TiO2/Fe3O4光催化复合材料．XRD，TEM对材料形态结构及包覆情况的分析，显示TiO2包覆在Fe3O4表面，形成平均尺寸为35～50nm的复合结构；UV-vis吸收曲线表明，复合材料对光的吸收出现红移，吸收强度增大；对染料废水光催化降解的模拟研究表明，该复合材料对活性艳红染料的脱色率达100％，是一种便于回收、可重复使用的高效光催化剂．     

硫化态NiW/Al2O3催化剂加氢脱硫活性相的研究Ⅰ.XPS和HREM表征

 采用孔饱和共浸法制备了一系列具有相同W含量和不同Ni含量的NiW/Al2O3催化剂,并对相应的硫化态催化剂进行了XPS和HREM表征. 结果表明,引入的助剂Ni优先修饰WS2晶粒的边角位置,形成高活性的NiWS相. 催化剂中助剂Ni在噻吩加氢脱硫反应中的显著促进效应(活性提高了约30倍)与形成的NiWS活性相数量有关. 同时,助剂Ni的引入使得催化剂表面WS2晶粒的堆叠程度略有增加,晶片长度略有减小;而且引入助剂后WOx相的硫化度提高了近20%. 但相比之下,活性相织构的变化和硫化度的增大对催化脱硫活性的贡献较小,不是Ni产生助剂效应的主要原因.     

Cr,Fe,Cu/Al2O3界面化学结构的光电子能谱

应用Ｘ－射线光电子能谱，通过离子刻蚀，原位研究第四周期过渡金属与氧化铝所形成界面的化学状态，结果表明，Ｃｒ，Ｆｅ在界面处有不同程度的氧化，氧化程度Ｃｒ＞Ｆｅ，而Ｃｕ则无明显氧化。化学成份的定量分析表明，界面过渡层的厚度与界面化学反应强弱直接相关。     

Fabrication and Visible Light Photocatalytic Activity of Co-doped ZnO Nanorods

Co-doped ZnO nanorods were prepared by electrochemical deposition method in aqueous solution. lb study the as-grown samples, several characterizations were carried out. The scanning electron microscopy（SEM） images show that the samples present a rod-like shape with hexagonal cross sections and roughened surthce. There is a slight shift for （002） diffraction peak of Co-doped ZnO nanorods in XRD because Co2~ ions entered into the ZnO lattice. Energy-dispersive X-ray spectroscopy（EDS） and X-ray photoelectron spectroscopy（XPS） results also show the exist of Co in the sample. Photoluminescence（PL） spectra of the samples were observed at room tempera- ture, the UV emission of Co-doped ZnO shows a slight red shift compared with that of undoped ZnO. Thus, we can reach the conclusion that Zn2＋ ions have been substituted by Co2. ions in the ZnO samples. In addition, photocatalysis property of Co-doped ZnO nanorods was investigated under the irradiation of visible light. It was found that the degradation rate of methyl orange is increased greatly nanorods. by Co-doped ZnO nanorods in comparison to undoped ZnO     

Characterizations and Photocatalytic Activities of Nanocrystalline MTiO3 （M = Sr, Pb, Co） Prepared via a General Self-propagating Combustion Method

Nanocrystalline MTiO3 (M=Sr, Pb, Co) were prepared by a general self-pro- pagating combustion method. The samples were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activity of MTiO3 (M=Sr, Pb, Co) was evaluated by the photocatalytic degradation of methyl orange (MO). MTiO3 (M=Sr, Pb, Co) having the same core element showed distinctly different photocatalytic activity due to the different coordinating atoms. Factors affecting the photocatalytic activity of MTiO3 (M=Sr, Pb, Co) were discussed. It was suggested that the structures of TiO6 octahedra and the electronic property were the predominant factors of the photocatalytic behavior for MTiO3 (M=Sr, Pb, Co).     

Au/Mn2O3/Al2O3催化剂的制备及其deNOx活性

由于燃煤烟气、汽车尾气的过度排放 ,大气中ＮＯｘ(其中ＮＯ占 90 %以上 )浓度已呈上升趋势。ＮＯ在阳光作用下 ,易形成光化学烟雾 ,危害人体的呼吸系统。ＮＯ还是破坏大气臭氧层和形成酸雨的前驱气体之一 ,破坏生态环境。催化分解和催化还原法是消除ＮＯ(ｄｅＮＯｘ)的主要方法。但由于实际环境中ＮＯ往往与某一种或几种还原性气体 (如ＣＯ、低碳烃 )共存 ,所以催化还原法是人们公认的有应用前景的ｄｅＮＯｘ 方法[1 ] 。近十几年来 ,国内外研究较多的ｄｅＮＯｘ 催化剂是Ｃｕ ＺＳＭ 5 ,其催化活性除受原料气中氧含量的影响外 ,很大程度上…     

TiO2/SiO2/Fe3O4的制备及其光催化性能

TiO2/SiO2/Fe3O4的制备及其光催化性能;磁栽;光催化;脱色作用;Oraange     

光催化材料Cu/Fe2O3-TiO2的结构和性能

光催化材料Cu/Fe2O3-TiO2的结构和性能;复合半导体;Cu/Fe2O3-TiO2;光催化材料;光响应性能     

二维钨-钒簇聚物[Cu（en）2]2·[WⅥ4·5WV2VVVⅣ9·5O44{Cu（en）2（H2O）}2]·3H2O的合成与表征

采用水热法合成了一个钨-钒簇聚物[Cu(en)2]2[WⅥ4.5WV2 VVVⅣ9.5O44{Cu(en)2(H2O)}2]·3H2O(1, en=乙二胺),并通过X射线单晶衍射、元素分析、傅里叶变换红外光谱、X射线粉末衍射、热重分析、价键计算、X射线光电子能谱、电子顺磁共振和磁性分析对其结构和性能进行了表征.结果表明,化合物1是以双支撑的四帽Keggin结构[WⅥ4.5WV2 VⅣ9.5O40(VVO4){Cu(en)2(H2O)}2]4-钨-钒簇合物阴离子为基本结构单元,与4个[ Cu( en)2]2+配合物阳离子以共价键和弱键相连接形成二维层状结构,相邻层又通过氢键连接成三维超分子网络.研究了化合物1的磁性及光催化降解罗丹明B的活性.     

Fe-Mn/Al2O3催化剂低温 NH3选择性催化还原 NO的性能

本文制备了一系列 Fe-Mn/Al2O3催化剂,并在固定床上考察了其 NH3低温选择性催化还原 NO的性能.首先考察了不同 Fe负载量制备的催化剂的脱硝性能,优选出最佳的 Fe负载量;在此基础上,研究了 Mn负载量对催化剂脱硝效率的影响;最后,对优选催化剂的抗 H2O和抗 SO2性能进行了实验研究;同时,对催化剂由于 SO2所造成的失活机制进行了考察.采用 N2吸附-脱附、X射线衍射、透射电镜、能量弥散 X射线谱、程序升温还原、程序升温脱附、X射线光电子能谱、热重和傅里叶变换红外光谱等方法对催化剂进行了表征.结果表明,最佳的 Fe和 Mn负载量均为8%,所制的8Fe-8Mn/Al2O3催化剂在150°C的脱硝效率可达近99%;同时,在整个低温测试区间(90–210°C)的脱硝效率均超过了92.6%. Fe在催化剂表面主要以 Fe3+形态存在,而 Mn主要包括 Mn4+和 Mn3+; Mn的添加提高了 Fe在催化剂表面的积累,促进了催化剂比表面积增大和活性物种分散,改善了催化剂氧化还原性能和对 NH3的吸附能力.催化剂的高活性主要是由于其具有较大的比表面积、高度分散的活性物种、增加的还原特性和表面酸性、较低的结合能、较高的 Mn4+/Mn3+和增强的表面吸附氧.此外,8Fe-8Mn/Al2O3的催化性能受 H2O和 SO2影响较小,抗 H2O和 SO2能力较强.同时,反应温度对催化剂的抗硫性有重要影响,在较低的反应温度下,催化剂抗硫性更好; SO2造成催化剂活性降低主要是由于催化剂表面硫酸盐物种的生成.一方面,表面硫酸铵盐的生成造成催化剂孔道堵塞和比表面积降低,减少了反应中的气固接触从而导致活性降低;另一方面,催化剂表面的活性物种被硫酸化,造成反应中的有效活性位减少,从而降低了催化剂活性.     

由钛铁矿制备Fe_3O_4/TiO_2复合物的研究进展

归纳了从钛铁矿中分离铁和二氧化钛的方法,包括亚熔盐法、预氧化法、还原锈蚀法;其次,初步总结了目前国内外制备Fe_3O_4磁性纳米颗粒和TiO_2纳米粒子的方法。最后,对Fe_3O_4/TiO_2复合材料的制备方法包括溶胶-凝胶法、微乳液法、均匀沉淀法作了梳理。Fe_3O_4/TiO_2复合纳米材料很好地解决了单独使用TiO_2作为废水处理催化剂,在实际应用过程中易随水流失,难以回收利用的问题,具有一定的实用性。     

LnCu2O4(Ln=Gd,Nd)电子结构的XPS研究

用XPS测定了LnCu2O4(Ln=Gd, Nd)的内层和价层电子能谱,观察到LnCu2O4中稀土金属的3d电子结合能比相应的稀土金属简单氧化物的3d结合能低0.8～0.9 eV,而Cu的2p电子结合能比CuO的高0.4～0.5 eV,因此推断在LnCu2O4的Ln－O－Cu链中存在Cu→O→Ln电荷转移.XPS分析还表明LnCu2O4的Cu原子上有较低的电荷密度,但不存在混合价态.此外,通过比较价电子能谱,发现NdCu2O4的Ln 4f Cu 3d O 2p价带中心比GdCu2O4的价带中心向Fermi能级移近了3.4 eV,而且NdCu2O4的价带谱更窄.