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1.
层状双金属氢氧化物制备与应用的研究进展   总被引:1,自引:0,他引:1  
LDHs是一类具有双金属氢氧化物层结构的新型无机功能材料,由于其具有酸碱性、层间阴离子可交换性等特性,在很多领域中得到广泛的应用.本文介绍了LDHs的成分与结构,综述了阴离子型层柱双金属的制备方法及其在催化材料、阻燃材料、防紫外线材料、医药材料等方面的研究进展.  相似文献   

2.
在SrO-Nb2O5系统中,通过掺杂Fe^3+,首次合成了具有正交钨青铜结构的新型铌酸盐晶体Sr6FeNb9O30,并对其进行了偏光显微镜观察、化学分析及X射线衍射结构分析。  相似文献   

3.
传统方法制备的稀土离子掺杂铌酸盐微纳米材料存在一定不足,因此在制备时通过改变稀土离子掺杂浓度对其进行改性,并研究性能表征。采用高温固相制备方法,经过原料配比、混合、抽滤烘干、添加助熔剂、热处理、研磨等流程,制备出稀土离子掺杂铌酸盐微纳米材料。实验证明:稀土离子掺杂浓度越低,材料的晶胞体积越大;稀土离子掺杂浓度越低,温度传感灵敏度越高。通过对比可知,该方法的原料转化率高,效率高,成本低,综合性能更优。  相似文献   

4.
金属有机骨架(metal-organic frameworks,MOFs)是一种新型的有机-无机杂化材料,因其比表面积大、孔隙度高、结构多样性及可调控等特点,已成为光催化领域研究的热点.综述了近年来MOFs作为光催化剂在光催化降解有机物、光催化氧化还原物质以及光催化产氢等方面的研究进展与现状,对MOFs光催化材料面临的问题和挑战进行了讨论,对其今后的发展进行了展望.  相似文献   

5.
介绍了高温压电材料的研究现状,综述了钙钛矿、钨青铜型、铋层状、碱金属铌酸盐结构体系4种不同压电陶瓷的结构及研究情况,并指出了高居里点压电陶瓷的研究方向和发展趋势。  相似文献   

6.
三种金属有机化合物作为客体交换嵌入层状磷锑酸钠层间,采用浸渍法制备,并采用TGA、IR、XRD等方法对其进行了表征,表明采用层状化合物有望获得有利于反应组分进出的分子空间通道.层状磷锑酸盐的层膨胀、回缩可逆、原有层结构不被破坏.嵌接担载大大改善了催化材料CuSb3bP2O14(Na)的抗失活稳定性,磷锑酸层间基因和静电场的协同作用改善了它的催化效果.  相似文献   

7.
以十六烷基三甲基胺为模板剂,钛酸正四丁酯为钛前驱体,草酸铌为铌的前驱体,用溶胶一凝胶手段,将铌元素引入到介孔二氧化钛体系中,制备出了介孔NbzO5Ti02复合氧化物。采用XRD、IR等表征手段对其进行表征,并以苯酚为目标降解物进行了光催化反应活性测试。结果表明:少量铌能进入TiO2骨架,样品保持介孔结构,当铌量进一步增加时,介孔结构遭到破坏;铌的掺杂并不能使介孔TiO2分子筛的光催化活性提高。  相似文献   

8.
采用水热法制备了石墨烯基二氧化钛复合光催化材料,运用多种分析手段(TEM、XRD、FT-IR、BET及UV-Vis)对其结构进行了表征,研究了其光催化分解水产氢的活性,探讨了材料组成、结构与性能之间的相互影响.结果表明,片状石墨烯与在其表面生长的纳米TiO2颗粒之间具有强烈的协同作用,不仅改善了光催化复合材料的比表面积...  相似文献   

9.
采用离子交换法合成了新型的杂多阴离子[CoW12O40]5-柱撑的水滑石[Mg2Al(OH)6]5[CoW12O40].26H2O.系统研究了以硝酸根型水滑石作为前体,通过插层组装制备杂多阴离子柱撑水滑石的反应条件及其控制规律,考察了杂多阴离子柱撑水滑石的组成、结构和性能之间的关系,通过XRD,FTIR等表征手段分别对杂多阴离子柱撑水滑石的晶相结构及其影响因素、红外光谱等进行了研究,并详细研究了光催化性能.  相似文献   

10.
文章将光催化领域的热点材料碘氧化铋材料的制备与研究转化为实验教学项目。实验采用简单的室温沉淀法制备了两种具有不同化学组成的碘氧化铋纳米微球,以苯酚为目标污染物,研究了碘氧化铋在可见光下对苯酚的降解性能,通过对催化剂结构的表征和构效关系的分析,探讨了影响催化剂光催化活性的主要因素。实验涉及纳米材料制备、结构表征、光催化原理以及污染物浓度分析等多个知识点。该实验有利于培养学生综合分析问题和解决问题的能力,以及科学思维与创新能力的提升。  相似文献   

11.
自从Honda和Fujishima发现太阳光照TiO2半导体电极能分解水产生氢气这一现象以来,科学家们一直致力于用半导体光催化剂和其它光催化剂用于太阳光解水获得既可储存又清洁的氢能的研究,不断地提高半导体光催化性能,而且也取得了令人瞩目的成果.本文综述了近年来在光催化水解领域中的众多半导体包括简单氧化物,复合氧化物,金属配合物和染料敏化半导体等光催化剂材料的结构、基本原理和催化特性的研究进展.  相似文献   

12.
采用共沉淀法合成了Ag2O/NaNbO3复合光催化剂,并利用X射线衍射(XRD)和扫描电子显微镜(SEM)分别对其物相和形貌进行表征,用紫外可见漫反射光谱仪对其光学性质进行研究。在可见光下以罗丹明B(RhB)为目标降解物,检测了Ag2O/NaNbO3光催化剂的光催化性能。结果表明,与纯的Ag2O和纯的NaNbO3相比,Ag2O/NaNbO3复合光催化剂具有较高的光催化活性,其光催化活性的提升可能归结于p-n结的形成,使得光生电子空穴对的复合机率大大降低。  相似文献   

13.
用柠檬酸络合法制备了尖晶石型复合氧化物CoAl2O4、CuAl2O4和ZnAl2O4,用XRD、TEM、Fr—IR和UV—Vis等手段对催化剂结构扫性能进行了表征,并考察了其在可见光下降解刚果红的催化性能。结果表明:在可见光条件下。60min内CuAl2O4使刚果红降解率达90%以上。  相似文献   

14.
In this study, a bulk composite material symbolized as NiCo LDH-rGO/Ni F was developed by a solvothermal process for the first time. This material was fabricated through simultaneous growth of nickel-cobalt layered double hydroxide(NiCo LDH) and reduced graphene oxide(rGO) on nickel foam. This bulk composite can be used directly as a binder-free electrode for supercapacitors(SCs). The physicochemical properties of this composite were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The electrochemical properties of the composite were measured by the cyclic voltammetry and galvanostatic charge-discharge. The results show that this composite had a hierarchical structure and exhibited a significantly enhanced specific capacitance of up to 3383 F/g at 1 A/g. The asymmetric SC using this composite as a positive electrode had a high energy density of 40.54 Wh/kg at the power density of 206.5 W/kg and good cycling stability. Owing to the synergies between the metal oxides and the rGO, the preparation method of in situ growth and its hierarchical structure, this bulk composite displayed excellent electrochemical performance and had a promising application as an efficient electrode for high-performance SCs.  相似文献   

15.
综述了近年来可见光响应型非TiO2基光催化剂的研究现状,包括结构简单的窄带光催化剂、钙钛矿型与尖晶石型光催化剂和钨锰铁矿型光催化剂,阐述了它们的制备方法、结构特点及光催化性能,并对今后的研究提出了展望.  相似文献   

16.
采用沉积沉淀法制备了四氧化三铁负载磷酸银(Ag3PO4/Fe3O4)可见光磁性催化剂,利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)对催化剂的微观形貌进行了表征。用甲基橙的光催化降解评价了不同负载量的Ag3PO4/Fe3O4复合催化剂的光催化性能。结果表明:当Ag3PO4负载量为50%时光降解效果最好,在模拟太阳光下,辐照80 min后的降解率可达到90%以上。  相似文献   

17.
The crystal form of TiO_2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO_2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO_2 on gaseous organic-pollutant photocatalytic degradation, we synthesized a series of TiO_2 nanoparticles with controllable phase ratios. We explored the role of the TiO_2 phase ratio on the photocatalytic activity and degradation pathway in the photodegradation of 2-propanol(IPA). We estimated the crystallite size and crystal proportions of anatase and rutile by X-ray diffraction. We used the Brunauer-Emmett-Teller method to calculate the specific surface area and Fourier transform infrared spectroscopy to characterize the surface chemistry of the samples. Our results show the photocatalytic activities of pure anatase and the sample with 8.6% rutile to be much better than those of the samples with a phase junction and pure rutile. As such, anatase is the better option for the study of photodegradation design and preparation of gas-phase organic pollutants.  相似文献   

18.
采用溶胶-凝胶法制备了膨胀石墨负载TiO2和负载氮掺杂TiO2(N-TiO2)光催化剂,用XRD和SEM对样品进行表征,并以甲基橙溶液为目标降解物进行光催化性能的评价。结果表明:纳米TiO2可牢固地负载在膨胀石墨表面和层间,当达到吸附平衡后,煅烧温度为500℃条件下制备的膨胀石墨负载N-TiO2光催化剂在加入量为10 g/L、反应时间60 min的条件下,对初始浓度为15 mg/L的甲基橙溶液的降解率达到95.2%。  相似文献   

19.
The crystal form of TiO2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO2 on gaseous organic-pollutant photocatalytic degradation, we synthesized a series of TiO2 nanoparticles with controllable phase ratios. We explored the role of the TiO2 phase ratio on the photocatalytic activity and degradation pathway in the photodegradation of 2-propanol (IPA). We estimated the crystallite size and crystal proportions of anatase and rutile by X-ray diffraction. We used the Brunauer–Emmett–Teller method to calculate the specific surface area and Fourier transform infrared spectroscopy to characterize the surface chemistry of the samples. Our results show the photocatalytic activities of pure anatase and the sample with 8.6% rutile to be much better than those of the samples with a phase junction and pure rutile. As such, anatase is the better option for the study of photodegradation design and preparation of gas-phase organic pollutants.  相似文献   

20.
Li  Han  Zhang  Junchao  Yu  Jiaguo  Cao  Shaowen 《天津大学学报(英文版)》2021,27(4):338-347

The photocatalytic reduction of CO2 is a promising strategy to generate chemical fuels. However, this reaction usually suffers from low photoactivity because of insufficient light absorption and rapid charge recombination. Defect engineering has become an effective approach to improve the photocatalytic activity. Herein, ultra-thin (~ 4.1 nm) carbon-doped Bi2WO6 nanosheets were prepared via hydrothermal treatment followed by calcination. The ultra-thin nanosheet structure of the catalyst not only provides more active sites but also shortens the diffusion distance of charge carriers, thereby suppressing charge recombination. Moreover, carbon doping could successfully extend the light absorption range of the catalyst and remarkably promote charge separation, thus inhibiting recombination. As a result, the as-prepared Bi2WO6 photocatalyst with ultra-thin nanosheet structure and carbon doping exhibits enhanced photocatalytic CO2 reduction performance, which is twice that of pristine ultra-thin Bi2WO6 nanosheet. This study highlights the importance of defect engineering in photocatalytic energy conversion and provides new insights for fabricating efficient photocatalysts.

  相似文献   

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