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表面修饰TiO2、ZrO2纳米微粒的DSC、TGA表征 总被引:2,自引:1,他引:2
采用DSC及TGA技术对制备的表面为硬脂酸修饰的二氧化钛及二氧化锆纳米微粒的热性能进行了研究,结合透射电的分析表征,结果表明,我们所得的TiO2,ZrO2纳米微粒表面确为硬脂民修饰,由于其纳米微粒核的存在使其表面修饰层的熔点温度高;此外表面修饰纳米闰由于其大的比表面积和不稳定的晶体结构使其分别在710K左右产生粘着和型变。 相似文献
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电化学法制备高热稳定性锐钛矿型纳米TiO2 总被引:8,自引:0,他引:8
以醇中加入少量有机腕导电盐作为电解液,以工业纯钛作“牺牲”阳性,控电流电解,可分别得到乙醇钛、异丙醇钛、正丁醇然等的相应醇溶液。然后直接水解,经溶胶-凝胶(Sol-gel)过程,形成凝胶前体,在450℃,720℃煅烧30min后,均得到高热稳定锐钛矿型(anatase)纳米TiO2(10nm左右)。通过FTIR,XRD,TEM等测试手段,对钛醇盐和纳米TiO2进行了表征。本文同时讨论了不同钛醇盐制 相似文献
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溶胶—凝胶法制备负载型TiO2膜的研究 总被引:1,自引:0,他引:1
本研究采用溶胶-凝胶(Sol-Gel)法制备了负载型TiO2膜,并采用SEM、压汞等实验手段对Ti(OH)4溶胶和TiO2膜进行了表征。实验表明:Ti(OH)4溶胶制备过程中H2O/Ti^4+、C2H5OH/Ti^4+的比值,溶胶在支承管上浸涂的时间、次数以及凝胶煅烧升温速度和煅烧温度均是制备负载型TiO2膜的重要因素。最终制得一种无裂纹、20μm厚、孔径分布在50 ̄300nm之间的负载型TiO2 相似文献
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甲苯气相选择氧化制苯甲醛 Ⅴ.K~+添加量对V_2O_5/TiO_2催化剂的影响 总被引:1,自引:0,他引:1
在V2O5/TiO2催化剂中添加K+,发现当K+/V摩尔比为0.04-0.07时,催化剂性能得到显著改善.利用BET、XRD、H2-TPR、O2-TPD-MS和化学分析法,研究了催化剂结构和性能变化.结果表明,随K+添加量的不同,V2O5/TiO2催化剂结构和表面活性氧性质发生了很大变化,从而影响了催化剂反应性能. 相似文献
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以硝酸根型水滑石作交换前驱体,通过离子交换法合成了过渡金属离子一、三钛取代的Keggin结构过氧钨硅杂多阴离子柱撑水滑石Zn2Al(OH)6-[SiW11(TiO2)O39]及Zn2Al(OH)6-[SiW9(TiO2)3O37],用元素分析、XRD、IR、XPS、化学分析等手段对产物的组成和结构进行了表征。结果表明,过氧杂多阴离子进入水滑石层间,使水滑石的层间距从0.92nm增加到1.47nm。 相似文献
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几种钛酸钾纤维的合成及其相关性研究 总被引:1,自引:0,他引:1
本文以K_2CO_3和TiO_2为主要原料,采用混练-干燥-煅烧三步法合成出了K_2Ti_2O_5、K_2Ti_4O_9、K_2Ti_6O_13三种形式的钛酸钾纤维物质。测定了它们的XRD、DTA-TG、SEM、ICP、激光拉曼等有关特征数据和谱图,并对它们之间的相互关系进行了研究。 相似文献
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SO_4~(2-)/TiO_2、PO_4~(3-)/TiO_2、BO_3~(3-)/TiO_2系列固体酸的酸性、结构和晶相的研究 总被引:1,自引:0,他引:1
制备了SO42-/TiO2(Ⅰ)、PO43-/TiO2(Ⅱ)、BO33-/TiO2(Ⅲ)系列固体酸。用IR、Raman光谱对该系列固体酸进行结构表征,结果表明SO42-与TiO2表面的结合为螯合式双配位结构和共价硫酸盐共存,PO43-与TiO2表面的结合为桥式三配位结构,BO33-与TiO2表面的结合为单齿单配位结构和螯桥混合式三配位结构共存。用由溶液中正丁胺的吸附等温线测定固体表面酸度的方法测定了样品的酸量,结果表明酸量大小为Ⅰ>Ⅱ>Ⅲ。用XRD技术对该系列固体酸进行考察,衍射图分析提示该系列固体酸主要都为锐钛矿型晶型,但Ⅰ、Ⅱ、Ⅲ中又各自夹杂其它不同的晶型 相似文献
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微乳法制备纳米TiO2 /SiO2的结构及光催化研究 总被引:1,自引:0,他引:1
Nanosized TiO2 and TiO2/SiO2 particles were prepared by hydrolysis of tetrabutyl titanate (TBOT) and tetraethyl orthosilicate (TEOS) in the TX-100 reverse microemulsion. These particles were characterized by TG-DSC, XRD, FTIR, TEM,N2 adsorption-desorption. Their photocatalytic activity was tested by degradation of methyl orange. The result shows that TiO2/SiO2 nanoparticles are with a monodispersed spherical phase and a uniform size distribution,and TiO2 particles are dispersed on the surface of SiO2. The band for Ti-O-Si vibration in FTIR was observed, the Ti-O-Si bond increased the stability of anatase TiO2, suppressed the phase transformation of titania from anatase to rutile. And due to the addition of SiO2, the average size of titania decreased from 38 nm in pure TiO2 to 5 nm in TiO2/SiO2. It was found, under UV light irradiation, TiO2/SiO2 particles showed higher activity than pure TiO2, and TiO2/SiO2(1/1) particles showed the highest photocatalytic activity on the photocatalytic decomposition of methyl orange, which was influenced by crystal structure, particle size, crystallinity and Surface area Characteristics. 相似文献
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TiO2纳米晶光催化降解铬酸根离子的研究 总被引:19,自引:0,他引:19
以二氧化钛为光催化剂,研究了溶液的pH值、铬酸根离子的初始浓度、通入的气体种类、氧化钛的载量等因素对铬酸根离子降解率的影响。同时合成了粒径小于10nm的锐钛矿相和金红石相氧化钛纳米晶来考察晶相和尺寸效应对降解率的影响。结果表明,锐钛矿的催化活性高于金红石相,两者的催化活性均大大高于市售的氧化钛微粉。 相似文献
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微乳法合成纳米SiO2/TiO2及其光催化性能 总被引:1,自引:0,他引:1
采用聚乙二醇辛基苯基醚(Triton X-100)/正己醇/环己烷/氨水微乳体系合成了纳米TiO2和SiO2/TiO2复合物,用X射线衍射、红外光谱和透射电镜对其结构进行了表征,并以甲基橙降解评价了其光催化性能,讨论了SiO2/TiO2摩尔比、晶相组成及粒径与光催化活性的关系.结果表明,SiO2/TiO2催化剂中形成了新的Ti-O-Si键和无定形SiO2;在纳米TiO2中复合SiO2能有效抑制锐钛矿向金红石的转变,增加锐钛矿的稳定性,并阻止TiO2晶粒的聚集生长.催化剂的光催化活性随金红石含量的增加而降低,加入适量SiO2能明显提高TiO2的光催化活性,其中摩尔比为1/7的SiO2/TiO2光催化活性最高. 相似文献
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TiO2 thin films with different crystalline structures were prepared by the CVD method. The relationship between photocatalytic activity of a TiO2 thin film and its crystalline type was investigated. These films were characterized by XRD and AFM. Their photocatalytic properties were tested by the degradation of NO2-. The results showed that the crystalline structures of TiO2 thin films are primary anatase and/or rutile when the preparation temperatures were less than 573 K and higher than 773 K respectively. When the preparation temperature was around 623 K, the structures of TiO2 thin films were mixed crystalline structure, which showed the highest catalytic activity. When the ratio of rutile to anatase in TiO2 thin films fell between 0.5 and 0.7, the highest catalytic activity for the degradation of NO2- was found. 相似文献
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Crystallization and photovoltaic properties of titania-coated polystyrene hybrid microspheres and their photocatalytic activity 总被引:1,自引:0,他引:1
The hybrid microspheres with polystyrene core coated by titania nanoparticles were prepared by miniemulsion polymerization, and the as-prepared samples were characterized by SEM, XRD, TG-DTA, XPS, and SPS techniques. TiO2 nanoparticles experienced two processes of phase transition, i.e., amorphous to anatase and anatase to rutile at the calcining temperature range from 400 to 1000 degrees C. The phase transformation temperature of TiO2 hybrid microspheres from anatase to rutile was increased by about 300 degrees C due to the blocking function of calcined polymer remainder. SPS results present that the band-gap of hybrid microspheres is 3.2-3.4 eV, which is larger than that of pure TiO2. The maximum intensity of the SPS signal is about 3 times larger for the hybrid material as compared to the pure TiO2. In addition, the photocatalytic degradation rate of TiO2 hybrid microspheres was 15% faster than that of pure TiO2 in the experiment of the photocatalytic degradation of methyl orange. 相似文献
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Gold nanoparticles located at the interface of anatase/rutile TiO2 particles as active plasmonic photocatalysts for aerobic oxidation 总被引:1,自引:0,他引:1
Tsukamoto D Shiraishi Y Sugano Y Ichikawa S Tanaka S Hirai T 《Journal of the American Chemical Society》2012,134(14):6309-6315
Visible-light irradiation (λ > 450 nm) of gold nanoparticles loaded on a mixture of anatase/rutile TiO(2) particles (Degussa, P25) promotes efficient aerobic oxidation at room temperature. The photocatalytic activity critically depends on the catalyst architecture: Au particles with <5 nm diameter located at the interface of anatase/rutile TiO(2) particles behave as the active sites for reaction. This photocatalysis is promoted via plasmon activation of the Au particles by visible light followed by consecutive electron transfer in the Au/rutile/anatase contact site. The activated Au particles transfer their conduction electrons to rutile and then to adjacent anatase TiO(2). This catalyzes the oxidation of substrates by the positively charged Au particles along with reduction of O(2) by the conduction band electrons on the surface of anatase TiO(2). This plasmonic photocatalysis is successfully promoted by sunlight exposure and enables efficient and selective aerobic oxidation of alcohols at ambient temperature. 相似文献
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研究了在CO气流中,处理温度对纳米管钛酸(NTA)脱水产物TiO2的结构及C3H6光催化氧化反应活性的影响.结果表明:NTA经CO高温处理后,样品未发生C掺杂,只有碳沉积发生;随着处理温度的升高,样品的比表面积大幅下降,与NTA在空气中焙烧处理相比,由锐钛矿向金红石TiO2转变的温度提前;CO处理后产物对C3H6均未表现出可见光催化性能,但具有紫外光催化活性,随着在CO气氛中处理温度的升高,紫外光催化活性降低. 相似文献