首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
程春萍 《稀土》2012,(5):69-75
采用溶胶-凝胶、超声分散和溶液沸腾法制备YAlO3/Fe掺杂ZnO复合物,在可见光的照射下,考察了酸性红B降解效果,并利用X-射线衍射(XRD)和扫描电子显微镜(SEM)对光催化剂进行了表征,同时研究了YAlO3的包覆量、YAlO3/Fe掺杂ZnO的量、可见光照射时间、处理温度和处理时间等因素对酸性红B降解率的影响,其降解过程也用HPLC进一步进行验证。结果表明,YAlO3/Fe掺杂ZnO在40 min酸性红B的降解率达到97.7%,表现出更好的光催化活性。  相似文献   

2.
程春萍 《稀土》2012,33(3):64-69
对TiO2半导体材料进行改性,分别通过溶胶凝胶、超声波分散和溶液沸腾的方法合成了Er3+∶YAlO3/Fe掺杂TiO2复合物光催化剂,并且采用XRD和SEM进行表征,研究了各种因素在太阳光照射下降解酸性红B的催化活性,也考察了Er3+∶YAlO3的包覆量、Er3+∶YAlO3/Fe掺杂TiO2的量、太阳光照射时间、酸性红B的初始浓度和氯化钠浓度等其降解过程用UV-Vis光谱进行检测。实验结果表明,加入上转光剂之后降解率大幅度增加,改性后的光催化剂可以有效地降解染料废水。  相似文献   

3.
以凹凸棒黏土(ATP)为基体,通过原位溶胶-凝胶工艺,制备出凹土基复合光催化剂(ATP-SnO2-TiO2)光催化甲醛。采用X射线衍射(XRD),透射电镜(TEM)等分析测试技术对复合体进行表征。考察制备条件对其物理结构和光催化性能的影响,并对不同光催化剂性能进行研究。结果表明,在凹凸棒黏土表面负载SnO2-TiO2后光催化性能得到明显提高,复合体中TiO2负载量为50%(质量比)、SnO2与TiO2质量比为1∶4、800℃煅烧的复合光催化剂活性最强,光照射3 h后对30 mg/L的甲醛溶液的降解率可达99%以上,显示出优异的光催化性能。  相似文献   

4.
程春萍 《稀土》2012,33(4):44-48
通过溶胶凝胶的方法制备了上转光剂Er3+∶YAlO3,然后通过超声分散和溶液沸腾的方法合成了Er3+∶YAlO3/TiO2-CdS复合物光催化剂。利用X射线粉末衍射(XRD)和扫描电镜(SEM)技术对Er3+∶YAlO3和Er3+∶YAlO3/TiO2-CdS复合物进行了表征。以酸性红B染料水溶液作为模拟污染物,通过可见声催化降解程度评估Er3+∶YAlO3/TiO2-CdS复合物催化活性,并且比较了Er3+∶YAlO3/TiO2和Er3+∶YAlO3/CdS光催化活性。最后,对Er3+∶YAlO3上转光剂的原理和Er3+∶YAlO3/TiO2-CdS复合物的声催化机理进行了讨论。  相似文献   

5.
WO3/TiO2薄膜光催化降解ARB性能研究   总被引:5,自引:2,他引:3  
采用溶胶-凝胶法,在玻璃珠表面涂覆均匀透明的WO3/TiO2薄膜,并制成光催化反应器对水溶液中酸性红B(ARB)的光催化降解进行了研究。采用XRD对催化剂进行了表征,讨论了催化剂的组成、煅烧温度、酸性红B的起始浓度、pH值、光照时间等因素对光催化反应活性的影响。结果表明:当ω(WO3)=4.0%,煅烧温度为500℃,[ARB]=20 mg.L^-1,pH=7.1,光照时间为8 h时,酸性红B的脱色率可达94.8%。  相似文献   

6.
500℃焙烧3 h条件下制备了摩尔比nSn∶nW=2∶1,含3.0%(质量分数,下同)La2O3的镧改性固体催化剂SnO2-WO3/La2O3,采用IR分析对其进行了表征。通过改变催化剂用量、30%H2O2用量、反应时间及催化剂重复使用性等因素,系统考察了该稀土改性双金属氧化物催化氧化环己酮合成己二酸的催化性能。实验结果表明,己二酸的适宜合成条件为:100 mmol环己酮,1.25 g催化剂SnO2-WO3/La2O3,50 mL 30%H2O2,回流反应7 h,目的产物己二酸收率达77.7%。SnO2-WO3/La2O3连续使用6次己二酸收率仍可接近40%。  相似文献   

7.
采用溶胶凝胶法制备了YFeO3和超声分散法制备了YFeO3/TiO2-SnO2和YFeO3/TiO2复合物,通过酸性红B的声催化降解来评价复合材料的催化活性,并与单一TiO2的声催化性能进行了比较。结果表明,YFeO3/TiO2-SnO2的声催化活性明显优于单一TiO2或YFeO3/TiO2。并且考察了声催化剂的处理温度和用量,超声照射时间和染料初始浓度等因素对酸性红B降解率的影响。  相似文献   

8.
以合成TiO2掺杂CeO2作为催化剂,以超声降解甲基橙反应为模型,研究了各种因素对TiO2掺杂CeO2催化超声降解甲基橙溶液的影响。结果表明,在TiO2(掺杂CeO2)催化剂作用下超声降解甲基橙的效果明显优于单纯以锐钛矿型TiO2催化时的情况。TiO2(掺杂CeO2)用量为0.5 g/L~1.0 g/L、超声波频率为25 kHz、输出功率为1.0 W/cm2、pH值为1.0~3.0时,初始浓度为20 mg/L的甲基橙水溶液在80 min左右基本可降解完全,COD的去除率达到了99.0%。  相似文献   

9.
刘莉 《稀土》2012,(5):59-63
以Y2O3/ZnO鼓泡空化降解有机染料进行初步的探讨,研究了鼓泡时间,染料初始浓度,催化剂的量对降解刚果红的影响等,不同染料的降解率的对比及可能的降解过程。  相似文献   

10.
采用溶胶-凝胶法制备了锐钛矿型TiO2,通过沉淀法成功将Ag2C2O4沉积于TiO2表面制备了Ag2C2O4/TiO2异质结。采用孔隙比表面分析仪(BET)、X-射线衍射仪(XRD)等对Ag2C2O4/TiO2异质结结构和光响应能力进行了表征;运用表面光电压仪(SPS)等对光催化剂的光生电荷分离特性进行了研究;考察了异质结光催化剂对模拟污染物罗丹明B的催化降解性能。结果表明:当Ag2C2O4/TiO2摩尔比为7.0%时,异质结光催化剂的光生电子-空穴分离速率最高,该光催化剂对罗丹明B的光催化降解性能最好。  相似文献   

11.
Nickel catalysts supported on CeO2-ZrO2-CeO2,ZrO2-Al2O3 and Al2O3 were prepared and characterized by means of X-ray diffraction(XRD),BET areas,H2 temperature-programmed reduction(H2-TPR),and X-ray photoelectron spectroscopy(XPS).Through the test of catalytic partial oxidation of methane(CPOM),Ni/CeO2-ZrO2-Al2O3 displayed the highest activity,which resulted from its largest BET area and best NiO dispersion.Furthermore,Ni/CeO2-ZrO2-Al2O3 maintained a long-time stability in CPOM,which was attributed to its best coking resistance among all the prepared catalysts.  相似文献   

12.
项南  郭玉峰  郭兴敏 《工程科学学报》2017,39(11):1669-1673
钒钛磁铁矿是烧结矿重要的原料之一,Ca3TiFe2O8作为钒钛烧结矿中矿物被发现之后,其生成机理尚不明确.本文采用X射线衍射分析、元素能谱分析和TG-DSC分析相结合的方法,研究了Ca3TiFe2O8的生成机理以及不同温度、CaO与TiO2含量下Ca3TiFe2O8的生成规律.实验结果表明,Ca3TiFe2O8由Ca2 Fe2O5和CaTiO3反应生成,即CaO和Fe2O3反应生成Ca2 Fe2O5;其后,与CaTiO3反应生成Ca3TiFe2O8.反应时间越长,Ca3TiFe2O8的生成量越大,但反应温度对Ca3TiFe2O8生成的影响并不明显.另外,还发现CaO含量越高,Ca3TiFe2O8越易于生成,而且等摩尔Fe2O3和CaO下只要存在TiO2,就会有Ca3TiFe2O8生成.   相似文献   

13.
Ce0.67Zr0.33O2-Al2O3 solid solution was prepared by the co-precipitation method. Fe2O3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe2O3 on Ce0.67Zr0.33 O2-Al2O3 in our experimental condition for catalytic combustion of methane was 8% ( mass fraction). The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe203 was 8% ( mass fraction), the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe2O3 was well dispersed on the Ce0.67Zr0.33O2-Al2O3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.  相似文献   

14.
YBa2Cu4O8/La2/3 Ca1/3 MnO3/YBa2Cu4O8 ( Y-124/LCMO/Y- 124) heterostructure was prepared by facing-target sputtering technique. The oscillatory superconducting transition temperature was observed when the thickness of LCMO d L is larger than critical thickness d L^CR. The metal-insulator transition temperature can only be detected at d L 〉 d L^CR. The dependence on the spacer layer in LCMO/Y-124 systems suggests strongly the interplay of ferromagnetic and superconducting couplings.  相似文献   

15.
为了保持应用已久的有汞测铁经典方法中的许多优点而减轻HgCl2对环境的污染的缺点,对方法中HgCl2的用量由5m^[1]减少为2ml进行理论上的探讨,并以试验结果加以论证。  相似文献   

16.
The reaction of 2, 6-^iPr2CbH3NHSiMe3 with Tb(CH2SiMe3)3(THF)2 in benzene at room temperature afforded a binuclear terbium complex Tb2 {μ-CH2 SiMe2 NC6 H3 ^iPr2 -2, 6}3(THF)3. X-ray diffraction revealed that Tb atoms were bridged by three methylene units. One Tb atom was six-coordinated by two nitrogen atoms, three methylene carbons, and one THF molecule, while the other Tb atom was six-coordinated by one nitrogen atom, three methylene carbons, and two THF molecules. Both Tb atoms adopted a distorted trigonal prism geometry.  相似文献   

17.
Employing Dy2O3, Al2O3, and SiO2 as starting materials, several series of Dy2O3-Al2O3-SiO2 sealing glass were prepared. The relationship between their coefficients of thermal expansion and the contents of Dy2O3, Al2O3, and SiO2 were studied respectively. Experimental results showed that Dy2O3 and Al2O3 had a positive effect on the coefficient of thermal expansion of glass, whereas, SiO2 had a negative effect. The coefficient of thermal expansion of glass showed an apparent linear relation to the contents of these three raw materials, from which an estimation model was built, to calculate the coefficient of thermal expansion of sealing glass. Relative errors of the calculating results to testing results were no more than 2%, which suggested that the estimation model was reasonable. This study provides a good theory reference for the practical utilizing of this sealing material, through which a proper glass composition for good sealing could be easily found.  相似文献   

18.
Catalytic combustion of methane was conducted by using a Cu-based catalyst prepared by the plasma-assisted impregnation method. The properties of the catalysts were surveyed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (H2-TPR). The results showed that the activity of CuO/ZrO2 with the CeO2 and Y2O3 was obviously increased compared with the CuO/ZrO2 catalyst, which was examined in relation to the structure and surface characteristics and might be correlated with their surface oxygen species and redox properties. Among the investigated catalysts, the Ce-CuO/ZrO2 sample exhibited the highest activity for methane combustion.  相似文献   

19.
WSi2/MoSi2复合粉末材料的机械合金化合成   总被引:3,自引:0,他引:3  
张厚安  刘心宇 《稀有金属》2001,25(4):282-285
通过机械合金化和热处理工艺成功地制备了MoSi2 50%(摩尔分数x)WSi2复合粉末材料,利用X射线衍射手段分析了相的形成过程,并从热力学和球磨能量角度比较了MoSi2和WSi2相生成的难易程度。球磨40h后在高于1000℃热处理可获得(Mo,W)Si2合金;因G^0(MoSi2)<G^0(WSi2),WSi2相较MoSi2难生成,其所需球磨能量分别为120.240kJ/g和30.060kJ/g。  相似文献   

20.
Conventional cathode material (LiCoO2) was modified by coating with a thin layer of La2O3/Li2O/TiO2 for improving its performance for lithium ion battery. The morphology and structure of the modified cathode material was characterized by SEM, XRD, and Auger electron spectroscopy. The performance of the cells with the modified cathode material was examined, including the cycling stability, the diffusion coefficient under different voltages, and the C-rate discharge. The results showed that the cell composed of the coated cathode material discharged at a large current density, and possesses a stable cycle performance in the range from 3.0 to 4.4 V. It was explained that the rate of Li ion diffusion increased in the cell while using La2O3/Li2O/TiO2-coated LiCoO2 as the cathode and the coating layer may act as a faster ion conductor (La2O3/Li2O/TiO2).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号