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1.
TritonX-100/C_(10)H_(21)OH/H_2O体系层状液晶中超微粒子材料CdS的合成沈明,郭荣,严鹏权,于卫里(扬州大学师范学院化学系扬州225002)关键词超微粒子,层状液晶,表面活性剂,TritonX-100,CdS超微粒子是指粒径?..  相似文献   

2.
微量Gd对Ag-Cu基合金再结晶的影响   总被引:1,自引:0,他引:1  
用硬度测量、示差扫描量热(DSC)、金相显微镜、透射电镜和X射线衍射分析等技术研究了富Ag的Ag~Cu合金和含微量Gd的Ag-Cu-Gd合金的再结晶。并根据Ag-Cu-Gd三元系相图及合金显微结构分析,讨论了微量Gd对Ag-Cu合金再结晶的影响。结果表明,在Ag-Cu合金中,微量Gd的添加,使其再结晶温度大幅度提高,再结晶激活能增加。  相似文献   

3.
应用CS2在Ag-S键中的单核插入物(PPh3)2Ag(S2CSPr3^iC6H2)与CH2Cl2-Pr^iOH混合溶剂反应,生成了一个中性的三核银簇合物,并用X射线单晶衍射法测定了其晶体结构。  相似文献   

4.
应用溶剂化金属原子浸渍(SMAI)法和普通浸渍(CI)法制备了三种不同摩尔比的γ-Al2O3负载Ni-Ag双金属催化剂。XRD和磁测定结果表明SMAI催化剂中Ni和Ag的粒度均小于金属含量相同的CI催化剂,SMAI催化剂中Ni和Ag未形成合金,而CI催化剂中Ni和Ag形成了合金。SMAI和CI催化剂都具有超顺磁性。XPS测定结果表明SMAI催化剂中零价Ni和Ag的含量均高于CI催化剂。SMAI催化剂Ni在表面含量高于体相,Ni在表面富集,而CI催化剂Ni在表面和体相的含量相同  相似文献   

5.
SMAI和CI法制备的Ni—Ag/SiO2催化剂的结构与催化性质研究   总被引:1,自引:0,他引:1  
应用溶剂化金属原子浸渍(SMAI)法和普通浸渍(CI)法制备了金属含量相同的SiO2负载Ni-Ag双金属催化剂。XRD和磁测定结果表明SMAI催化剂中Ni和Ag的粒度均小于金属含量相同的CI催化剂,SMAI催化剂中Ni和Ag未形成合金,而CI催化剂中Ni和Ag形成了合金。SMAI和CI催化剂都具有超顺磁性。研究了这些催化剂在甲苯加氢反应的催化性质,结果表明与组成相同的普通浸渍法催化相比,SMAI催  相似文献   

6.
本文运用TPD-MS、TPR等方法研究了Ag/γ-Al_2O_3催化剂的氧脱附和还原性能。结果表明,Ag/γ-Al_2O_3催化剂表面银物相由Ag0和Ag+(Ag2O)组成,其中Ag+所占比例随负载量增加而减少。Ag/γ-Al_2O_3催化剂有三个脱氧峰,并且随着Ag负载量的增加,脱氧峰从高温向低温依次出现。低温脱氧峰(370℃)归属为结晶态Ag2O的分解,高温脱氧峰(650和800℃)为分散在γ-Al_2O_3表面并且与Al_2O_3发生相互作用的Ag_2O的分解。TPR有三个还原峰;高温峰(230℃)为结晶态Ag_2O的还原,低温峰(100和120℃)为分散在γ-Al_2O_3表面的Ag_2O的还原。  相似文献   

7.
夏泽吉 《大学化学》1994,9(6):53-54
对Ag(NH_3)_2~+中的Ag~+是sp杂化成键的商榷夏泽吉(四川达县师专化学系635000)目前在国内一些高等院校使用的《无机化学》[1,2]教材中,对Ag(NH3)配离子中的Ag(Ⅰ)均认为是sp杂化成键,而且有的《无机化学》[3]为了强调形成配...  相似文献   

8.
Ag/γ—Al2O3催化剂的TPR和TPD研究   总被引:1,自引:0,他引:1  
本文运用TPD-MS,TPR等方法研究了Ag/γ-Al2O3催化剂的氧脱附和还原性能,结果表明,Ag/γ-Al2O3催化剂表面银物相由Ag^0和Ah^+(Ag2O)组成,其中,Ag^+所占比例随负载量增加而减少。  相似文献   

9.
应用溶剂化金属原子浸渍法制血了四中不同比表面积树脂固载的Co-Ag双金属催化剂。射线衍射(XRD)和磁测定结果表明,随着树脂比表面积的增大,具有相同金属含量的催化剂Co和Ag的颗粒减小,分散度增大,因而催化剂在二丙酮醇加氢以及燃料电池电极上氧还原的催化活性增大。  相似文献   

10.
THEGEOMETRYANDORBITALINTERACTIONSOFTRIATOMICCLUSTERSOFCu,Ag(I)¥HanXingLIU(AdvancedMaterialsResearchInstitute,WuhanUniversityo...  相似文献   

11.
超细银粉在太阳能电池正面电极领域有广阔的应用前景,其粒径分布、分散性、表面态与其性能息息相关。 本文通过在液相还原法合成超细银粉的后期引入氧化石墨烯(GO),利用溶液状态下二者相对活性的表面的相互作用获得了性能优良的银粉。 通过X射线衍射(XRD)、拉曼光谱(Raman)和扫描电子显微镜(SEM)等手段对所得复合超细银粉进行结构及形貌表征,结果显示该法获得的银粉分散性较好、尺寸分布较窄。 进而,利用紫外-可见光谱探讨了GO与银粒子之间的相互作用。 而且研究发现:固定硝酸银溶液的浓度,随着GO含量的增加,银粉的导电性能先升高后降低,当GO的质量分数为2.5%时,导电性能更好。 这为超细银粉在实际中的应用提供重要数据和有益参考。  相似文献   

12.
The electrochemical behavior of PEDOT/Ag composite films obtained by chemical deposition of ultrafine Ag particles into the poly-3,4-ethylenedioxythiophene (PEDOT) matrix was studied. The film morphology was characterized by transmission electron microscopy (TEM). The changes in the mass of the films during the chemical deposition of silver into the polymer structure were evaluated microgravimetrically. The mass of the included metallic silver particles depends on the synthesis time and the initial concentration of silver ions in solution. The cyclic voltammograms (CVs) of PEDOT/Ag films in sodium nitrate solutions and sodium nitrate solutions with additions of chloride ions were studied. The cyclic voltammograms of PEDOT/Ag films in chloride-containing solutions showed the peaks of the oxidation of silver and reduction of the oxidation product, which were absent on the CVs of the starting PEDOT film.  相似文献   

13.
同轴静电纺丝法在纳米中空Ti02纤维中填充Ag的应用   总被引:2,自引:0,他引:2  
以聚乙烯吡咯烷酮(PVP)溶胶,钛酸四正丁酯和PVP溶胶,银颗粒为前驱体,以共轴静电纺丝法制备了银填充的TiO2中空纳米纤维.将双组分纤维在200℃下热处理去除乙醇与表面吸附水后,继而在空气气氛中焙烧至600℃.可以得到在内表面上沉积银颗粒的TiO2纳米管,银颗粒的直径为5-40 nm,TiO2纳米管的外径150-300 nm.管臂厚10-20 nm.用红外吸收光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等测试手段对超细纤维进行了表征.中空纤维的直径和管壁可以通过改变电纺参数来调节.与Ag-TiO2纳米纤维、TiO2纳米中空纤维、TiO2纳米纤维及TiO2纳米粉体相比较,Ag颗粒填充的TiO2纳米中空纤维在光分解亚甲基蓝上表现出了更好的光催化性能.  相似文献   

14.
The ultrafine powders of silver are prepared by the method of electrochemical deposition on cathode from water-ethanol solutions. Distribution of particles by size and quality of the synthesized powders are determined. A comparative evaluation of antimicrobial activity of silver nano-sized particles and foil is performed.  相似文献   

15.
同轴静电纺丝法在纳米中空TiO2纤维中填充Ag的应用   总被引:1,自引:0,他引:1  
以聚乙烯吡咯烷酮(PVP)溶胶/钛酸四正丁酯和PVP溶胶/银颗粒为前驱体, 以共轴静电纺丝法制备了银填充的TiO2中空纳米纤维. 将双组分纤维在200 ℃下热处理去除乙醇与表面吸附水后, 继而在空气气氛中焙烧至600 ℃, 可以得到在内表面上沉积银颗粒的TiO2纳米管, 银颗粒的直径为5-40 nm, TiO2纳米管的外径150-300 nm, 管臂厚10-20 nm. 用红外吸收光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等测试手段对超细纤维进行了表征. 中空纤维的直径和管壁可以通过改变电纺参数来调节. 与Ag-TiO2纳米纤维、TiO2纳米中空纤维、TiO2纳米纤维及TiO2纳米粉体相比较, Ag颗粒填充的TiO2纳米中空纤维在光分解亚甲基蓝上表现出了更好的光催化性能.  相似文献   

16.
银-金红石复合纳米微晶的光谱性能   总被引:3,自引:0,他引:3  
刘云  刘春艳  张志颖 《化学学报》2000,58(4):397-401
λ>330nm光照射含有金红石型TiO2微晶颗粒的AgNO3溶液,制备出了Ag-TiO2复合超微粒子,与纯的银溶胶相比,复合粒子上银的等离子体吸收峰宽化红移,位于400~600nm。这种复合超微粒子的溶胶,表现出表面增强拉曼散射(SERS)效应。吸附-共振增强可用来解释Ag-TiO2复合粒子的SERS效应。  相似文献   

17.
NiO-loaded NaTaO(3) doped with lanthanum showed a high photocatalytic activity for water splitting into H(2) and O(2) in a stoichiometric amount under UV irradiation. The photocatalytic activity of NiO-loaded NaTaO(3) doped with lanthanum was 9 times higher than that of nondoped NiO-loaded NaTaO(3). The maximum apparent quantum yield of the NiO/NaTaO(3):La photocatalyst was 56% at 270 nm. The factors affecting the highly efficient photocatalytic water splitting were examined by using various characterization techniques. Electron microscope observations revealed that the particle sizes of NaTaO(3):La crystals (0.1-0.7 microm) were smaller than that of the nondoped NaTaO(3) crystal (2-3 microm) and that the ordered surface nanostructure with many characteristic steps was created by the lanthanum doping. The small particle size with a high crystallinity was advantageous to an increase in the probability of the reaction of photogenerated electrons and holes with water molecules toward the recombination. Transmission electron microscope observations and extended X-ray absorption fine structure analyses indicated that NiO cocatalysts were loaded on the edge of the nanostep structure of NaTaO(3):La photocatalysts as ultrafine particles. The H(2) evolution proceeded on the ultrafine NiO particles loaded on the edge while the O(2) evolution occurred at the groove of the nanostep structure. Thus, the reaction sites for H(2) evolution were separated from those of O(2) evolution over the ordered nanostep structure. The small particle size and the ordered surface nanostep structure of the NiO/NaTaO(3):La photocatalyst powder contributed to the highly efficient water splitting into H(2) and O(2).  相似文献   

18.
Biodegradable poly(l-lactide) (PLA) ultrafine fibers containing nanosilver particles were prepared via electrospinning. Morphology of the Ag/PLA fibers and distribution of the silver nanoparticles were characterized. The release of silver ions from the Ag/PLA fibers and their antibacterial activities were investigated. These fibers showed antibacterial activities (microorganism reduction) of 98.5% and 94.2% against Staphylococcus aureus and Escherichia coli, respectively, because of the presence of the silver nanoparticles.  相似文献   

19.
用透射电子显微镜观察一步摄影正片(明胶介质)的银颗粒,对影响银颗粒大小的因素进行了研究。卤化银负片乳剂中的碘含量,明显地影响卤化银颗粒大小和转印后银颗粒的大小,随着卤化银乳剂中的碘含量减少,卤化银颗粒和银质点簇(即银颗粒)变大,组成银质点簇的银质点数目增多,正象色调由棕向黑转移。不同物理显影核亦显著影响正片银颗粒大小与其色调。  相似文献   

20.
Formation mechanisms of silver (Ag) particles in an aqueous ethanol solution of poly(N-vinyl-2-pyrrolidone) (PVP) by the photoreduction of AgClO(4) were investigated by means of in situ small-angle X-ray scattering (SAXS) measurements. The kinetics of association process (nucleation, growth, and coalescence) of Ag(0) atoms to produce Ag particles was successfully revealed by the quantitative SAXS analysis for the number-average of radius (R(0)), number of particles (n(Ag)), reduced standard deviation (σ(R)/R(0)), and volume fraction (?(Ag)) of Ag particles produced by the photoreduction. The rate of nucleation and growth process during Ag particle formation strongly depend on the initial metal concentration. The time evolution of radius and number of Ag particles indicates that a mechanism of Ag particle formation is composed of different three processes, that is, reduction-nucleation, Ostwald ripening, and particle coalescence. In a rapid reduction-nucleation process, small nuclei or particles (average radius ~2.5 nm) are produced by an autocatalytic reduction. After the formation of small nuclei or particles proceeds, Ostwald ripening and particle coalescence, predicted by the Lifshitz-Slyozov-Wagner theory (LSW theory), subsequently occur, resulting in the particle growth (average radius ~11.5 nm).  相似文献   

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