甲基橙的催化氧化降解工艺研究

分别采用紫外光照射、超声波辐射、纳米NiO催化3种方法及其相互协同作用对模拟印染废水甲基橙溶液进行催化氧化降解研究.结果表明,超声波辅助纳米NiO催化氧化降解模拟印染废水甲基橙溶液的效果显著优于紫外光照射、纳米NiO催化及其相互协同作用.     

纳米Au-Pd@Ce修饰介孔磷酸铝的制备及其催化氧化环己烷性能

采用水热合成法制备Ce修饰介孔磷酸铝,再通过原位还原法负载纳米Au-Pd制备催化剂;通过以空气为氧化剂的环己烷选择性氧化反应测试催化剂的催化性能,并考察水热温度、Ce掺杂量、负载贵金属对催化剂催化氧化环己烷的的影响。结果表明,以140℃水热制备的Ce掺杂质量分数为0. 15%的Ce0. 15-APO(140)负载Au-Pd双金属(Au与Pd质量比3∶1)催化剂活性最高。在反应温度120℃,空气压力1 MPa和反应1 h的条件下,环己醇+酮的产率可达11. 81%,选择性达99%,催化剂在同样条件下循环使用5次,活性无明显下降。     

正交法研究纳米Ce/TiO2的制备

纳米TiO2是一种重要的半导体光催化剂,在众多领域具有广阔的研究及应用前景。以稀土Ce为掺杂元素,采用溶胶-凝胶法制备了Ce掺杂纳米TiO2(纳米Ce/TiO2),通过XRD、BET、SEM等技术对其进行表征。设计L9(34)正交实验研究了不同条件对纳米Ce/TiO2的结构及表面特征的影响,优化了纳米Ce/TiO2的制备条件。初步研究了Ce/TiO2的光催化抗菌性能,表明Ce掺杂能够改善纳米TiO2的光催化抗菌性能。     

水热法合成Ce_（0.9）Gd_（0.1）O_（1.95）及其光催化性质研究

采用水热法合成了花状Ce0.9Gd0.1O1.95纳米粉,通过X射线衍射、红外光谱、场发射扫描电子显微镜测试手段对产物进行了表征,探讨了其生长机制,以亚甲基蓝的光降解为模型反应,研究其光催化性能。结果表明,以甲酸为介质,110℃的水热条件下合成的纳米Ce0.9Gd0.1O1.95颗粒经800℃煅烧后具有萤石结构,平均晶粒尺寸为21.6 nm,花状形貌;由于Gd3＋的掺杂,纳米Ce0.9Gd0.1O1.95对亚甲基蓝紫外光催化性能强于未掺杂的CeO2。该合成方法简单易行,对纳米Ce0.9Gd0.1O1.95的形貌控制起到了启示作用,所得的花状纳米Ce0.9Gd0.1O1.95在光催化领域有着重要应用价值。     

水热法合成Ce0.9Gd0.1O1.95及其光催化性质研究

采用水热法合成了花状Ce0.9Gd0.1O1.95纳米粉,通过X射线衍射、红外光谱、场发射扫描电子显微镜测试手段对产物进行了表征,探讨了其生长机制,以亚甲基蓝的光降解为模型反应,研究其光催化性能。结果表明,以甲酸为介质,110℃的水热条件下合成的纳米Ce0.9Gd0.1O1.95颗粒经800℃煅烧后具有萤石结构,平均晶粒尺寸为21.6 nm,花状形貌;由于Gd3+的掺杂,纳米Ce0.9Gd0.1O1.95对亚甲基蓝紫外光催化性能强于未掺杂的CeO2。该合成方法简单易行,对纳米Ce0.9Gd0.1O1.95的形貌控制起到了启示作用,所得的花状纳米Ce0.9Gd0.1O1.95在光催化领域有着重要应用价值。     

特定形貌和多孔纳米CeO_2的制备及其CO催化氧化研究进展

Ce是一种用途十分广泛的稀土金属,其金属氧化物Ce O_2由于具有优异的储放氧性能,使其在氧化还原、有机合成和有机污染物降解等反应过程中呈现出良好的催化性能,尤其是在CO的催化氧化反应中表现出了优异的活性。本文综述了纯Ce O_2及复合Ce O_2催化剂的制备方法、形貌与孔道控制及其对CO催化氧化性能等方面的最新研究进展。首先介绍了液相法、固相法和气相法等不同合成纳米Ce O_2的方法,通过对不同制备方法的工艺、成本、合成条件分析对比后,对其优缺点进行了系统的总结。随后讨论了利用不同制备方法及添加不同表面活性剂或模板剂所制备出的特定形貌及多孔纳米Ce O_2催化剂对CO的催化氧化性能,描述了Ce O_2对CO催化氧化的作用机理及形貌结构对催化性能的影响。最后根据对相关结果的总结发现,特定形貌及多孔结构的纳米Ce O_2催化CO活性虽有提高,但存在结构不稳定、工艺复杂等问题。而且,对于催化反应过程中的反应机理,形貌与结构变化的研究较少。希望在今后的工作中简化制备工艺,提高Ce O_2材料结构的稳定性,并用原位表征、模拟计算等方法来探究CO的氧化机理。     

铈掺杂纳米二氧化钛可见光光催化降解苯酚性能

研究了Ce掺杂纳米二氧化钛作为光催化剂,在可见光条件下光催化降解苯酚的过程,并分别测试了Ce掺杂量、锻烧温度、焙烧时间、pH值以及催化剂用量等因素对苯酚溶液光催化降解过程的影响,同时总结了铈掺杂纳米二氧化钛可见光光催化降解苯酚性能的最佳条件,以希冀给予相关研究人员一些可行性的帮助和指导。     

铁铈共掺TiO_2/复合白土光催化剂的合成及工业废水处理活性

以钛酸四正丁酯为原料,采用溶胶-微波法(Sol-microwave method)合成了铁和铈共掺型纳米TiO_2粉体(Fe-Ce-TiO_2),借助XRD、XPS和UV-vis等测试手段对其进行了表征,并以甲基橙为模型污染物考察了掺杂量对样品光催化活性的影响规律.XRD分析表明,所得粉体均为锐钛矿相纳米TiO_2,且过渡金属铁和元素稀土铈掺杂后纳米TiO_2特征衍射峰宽化,强度降低;XPS分析表明,镧和铈掺杂后样品表面存在大量的氧缺位;UV-vis吸收光谱表明,所得粉体在400 nm以下均有连续宽化的吸收带,且Fe和Ce掺杂后样品对光的吸收显著增强,这是由于Ce(Ⅳ) f →d 跃迁和Ce(Ⅳ)-O荷移跃迁所致;光催化实验表明,Fe和Ce共掺杂能显著提高纳米TiO_2的光催化活性,其中当Fe(Ⅲ)和Ce(Ⅳ)掺杂量分别为0.1%和0.04%时,纳米TiO_2 光催化剂具有较高的催化活性,自然光照下光催化氧化处理卷烟厂蒸叶车间废水,效果较好,废水COD去除率达到89.8%.且催化剂易沉降分离、重复使用性能稳定.     

燃烧合成Ag、La掺杂纳米TiO2及光催化性能研究

采用燃烧合成法制备了Ag、La掺杂纳米TiO2.XRD实验表明,La掺杂TiO2为单一相锐钛矿结构,Ag掺杂TiO2中出现了少量金红石相,与未掺杂纳米TiO2比较,Ag、La掺杂使TiO2晶体粒度更小,约8 nm.TEM实验表明,产物粒度分布均匀.用掺杂纳米TiO2降解罗丹明B,研究了元素掺杂量对TiO2催化性能的影响.结果表明,当Ag和TiO2摩尔比为1∶150、La和TiO2摩尔比为1∶75时,两种材料的催化能力最好,均优于未掺杂TiO2.比较Ag、La掺杂TiO2的催化性能,La掺杂TiO2的催化能力更强,在实验条件下,紫外光照射1.5 h,罗丹明B的降解率为99.0%.     

纳米氧化镍的乙烷氧化脱氢催化性能研究

采用溶胶-凝胶法制备了纳米氧化镍催化剂,其具有较好的低温催化乙烷氧化脱氢(ODHE)性能,通过SEM和XRD表征了该催化剂的形貌和结构,并研究了纳米NiO催化下ODHE反应的影响因素.     

Magnetic and antibacterial studies of sol-gel dip coated Ce doped TiO2 thin films: Influence of Ce contents

Ce-doped TiO₂ thin films were synthesized by sol-gel dip coating route to evaluate the effect of Ce doping percentage on properties of TiO₂. X-ray diffraction spectra revealed both anatase and brookite phases, and Ce doping favours the anatase–brookite transformation of TiO₂ films. The optical constants of the thin films were achieved by evaluating spectroscopic UV-VIS-NIR spectrophotometry data. The band gap of the Ce doped TiO₂ was reduced from ~3.93 eV to ~3.79 eV with an increase in Ce doping percentage. All films have shown ferromagnetic behaviors which increase with the increase in Ce content due to enhancement in the bound magnetic polaron. Higher Ce doping increases the oxygen vacancies and saturation magnetization. Boost magnetic properties stem from the generation of the interaction between the Ce ion and an oxygen vacancy. The study showed that the antimicrobial activity of Ce doped TiO₂ is ineffective. Hence doping of Ce can modify the properties of TiO₂ and are used in LEDs, magneto-optical devices and solar cells.     

Effect of In, Ce and Bi dopings on sintering and dielectric properties of Ba(Zn1/3Nb2/3)O3 ceramics

In, Ce and Bi doped Ba(Zn_1/3Nb_2/3)O₃ (BZN) ceramics were prepared by conventional mixed oxide technique. In doping between 0.2 and 4.0 mol% increased the density of BZN at 1300 °C, Ce doping caused a decrease in density at 1250 °C. Levels of Bi₂O₃ up to 1.0 mol% had negative effect on densification, while high level doping could significantly improve the densification of the specimens. XRD of the samples indicated that In, Ce and Bi doping resulted in single phase formation at all concentrations, except 0.5 mol% Bi. SEM of Bi doped BZN indicated only single phase structure and Ce doping even at 0.2 mol% gave some secondary phases. In and Ce doping increased the dielectric constant from 41 to around 66 at 1 MHz. Bi doping decreased the dielectric constant to about 37 at 0.2 mol%, and then higher doping led to dielectric constant to increase to about 63.     

纳米NiO掺杂Carbores'P对Al2O3-C耐火材料力学性能的影响

为提高低碳铝碳耐火材料的力学性能,以≤1 mm的棕刚玉、Si粉和Carbores’P为原料,外加纳米NiO为催化剂,制备Al2O3-C基质试样,利用XRD、SEM、激光拉曼光谱研究纳米NiO对Carbores’P炭化产物的影响。以棕刚玉(粒度为5~3、3-1、≤1 mm)、电熔白刚玉粉、Si粉、鳞片石墨、Carbores’P、纳米NiO为原料制备低碳Al2O3-C试样,研究纳米NiO掺杂Carbore’P对试样力学性能的影响。结果表明:1400℃埋碳热处理后,添加纳米NiO能提高基质的石墨化度,促进碳纳米管和SiC晶须的生成;正是由于它们的生成,提高了Al2O3-C试样的致密度、常温强度和断裂前的位移量,使试样韧性增强。     

基于光催化降解甲醛溶液性能的Cu-Ce/TiO2制备方案的响应面法优化

采用溶胶-凝胶法,以过渡金属Cu离子和稀土金属Ce离子改性TiO2制备Cu-Ce/TiO2,基于响应面和数值模拟方法研究Cu-Ce负载量(Cu-Ce含量)、Cu/Ce摩尔比及烧结温度对Cu-Ce/TiO2光催化降解甲醛溶液性能的影响,对Cu-Ce/TiO2制备方案进行优化,并对最佳条件下制备的Cu-Ce/TiO2进行表征. 结果表明,三个因素均对Cu-Ce/TiO2的光催化性能有影响,其影响显著性为：烧结温度>Cu-Ce负载量>Cu/Ce摩尔比. 优化的制备条件为：Cu-Ce负载量2.88%(mol), Cu/Ce摩尔比1.6364,烧结温度544℃. Cu-Ce共同改性TiO2能有效避免掺杂TiO2晶格内部表层和近表层产生较多的位错,抑制晶格畸变增大,诱导TiO2中锐钛矿型晶体向金红石型晶体转变的能力增强,提高粒径均匀性和分散性能.     

New Magneto‐Optical Film of Ce,Ga:GIG with High Performance

Ce³⁺‐doped Gd₃Fe₅O₁₂ (Ce:GIG) film has a good application prospect in the field of integrated optical device. In this article, Ce:GIG and Ce,Ga:GIG films were deposited onto the quartz glass substrate by using radio‐frequency magnetron sputtering technology. The crystal phase, surface morphology, magnetization, and magnetic circular dichroism properties of films were characterized by using the X‐ray powder diffraction, atomic force microscopy, vibrating sample magnetometer, and circular dichroism spectrometer. The results show that as‐prepared Ce,Ga:GIG films has a good quality and show an excellent magneto‐optical performance, and the doping of Ga³⁺ ion and the annealing process have significant effect on the magnetism and magneto‐optical performances. It is expected that Ce,Ga:GIG film with a moderate Ga³⁺‐doping content is a better candidate than Ce:GIG and Ce:YIG films for the next generation of integrated optical isolator and other magneto‐optical equipment.     

不同碱土金属氧化物掺杂对纳米二氧化铈催化性能的影响

通过水热法制备了平均粒径约为20nm的CeO₂,并在纳米CeO₂上引入不同浓度的3种碱土金属氧化物（MgO、CaO和BaO）。催化结果显示在用于催化二氧化碳和甲醇直接合成碳酸二甲酯（DMC）的反应中,此3种碱土金属氧化物均未对纳米CeO₂的催化活性起到促进作用。此外通过透射电镜（TEM）、X射线衍射（XRD）、比表面积及孔分布测试（BET）、X射线光电子能谱（XPS）和程序升温吸附（TPD）对所制备的催化剂进行了表征。研究结果表明,少量的碱土金属氧化物的掺杂不会导致CeO₂晶格变形,而是以无序的形式存在;且碱土金属氧化物的掺杂对纳米CeO₂的形貌、尺寸和织构性质影响不大,对其表面的Ce（Ⅳ）/Ce（Ⅲ）和酸碱性位的数量以及强度有较大影响。此外,较高的Ce（Ⅳ）/Ce（Ⅲ）和较多的酸性位是影响纳米CeO₂催化性能的重要因素。     

Fabrication of fibrous poly (ɛ-caprolactone) nano-fibers containing cerium doped-bioglasses nanoparticles encapsulated collagen

Novel nanosized designed ceramic powders, cerium (Ce) doped bioglass (BG) with various doped Ce content, were synthesized by sol–gel method in order to be employed in the development of PCL fibrous scaffold for bone tissue engineering applications. Characterization techniques such as X-ray diffraction analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy were employed to evaluate the developed Ce doped BG powders. The results confirmed successful doping of Ce inside BG structure. 0, 1, 3, and 10 wt% Ce doped 58S BG were successfully encapsulated in the collagen microspheres by water-in-oil emulsion method and the average particle size and hydrodynamic diameter of microspheres were determined using scanning electron microscopy and dynamic light scattering analysis, respectively. Next, 0, 1, 3, and 10 wt% Ce doped 58S BG encapsulated collagen microspheres were loaded inside the Poly(ɛ-caprolactone) fibrous scaffold and their in vitro bioactivity and biocompatibility properties were evaluated. The results of soaking samples in the simulated body fluid showed that all Ce doped 58S BG encapsulated collagen microspheres loaded PCL fibrous scaffold have acceptable bioactivity and apatite formation ability over time. The biocompatibility evaluation of developed scaffolds showed high viability and proliferation of MG63 cells cultured on the surface of 3% Ce doped 58S BG encapsulated collagen microsphere loaded in the PCL fibrous scaffold and its high potential ability for bone tissue engineering applications. These results potentially open new aspects for scaffolds aimed at the regeneration of bone defects.     

掺铈纳米TiO2的制备及其对光催化性能的影响

为改进和提高纳米二氧化钛光催化剂的催化性能,利用硝酸铈及钛酸丁酯为主要原料,通过溶胶-凝胶法制备纳米掺铈二氧化钛光催化剂,并用TGA、XRD、BET等方法对粒子进行表征,并通过其催化降解亚甲基兰来研究其催化活性影响.结果表明：铈掺杂法制备的纳米级二氧化钛,降低了粒子半径,提高了比表面积和催化活性;在较低的浓度范围内,随着掺杂量增加,光催化活性增加,2.3%TiO2光催化活性最高.     

稀土掺杂TiO2光催化还原CO2

采用溶胶-凝胶法制备了稀土掺杂TiO₂纳米光催化剂,并应用于光催化还原CO₂/H₂O体系中。通过XRD对光催化性能进行表征,研究稀土离子掺杂和焙烧温度对光催化性能的影响。结果表明,稀土La和Ce的加入可以抑制TiO2的晶相转变,提高光催化性能。催化剂800 ℃焙烧可达到最好的光催化活性,在反应时间7 h、CO₂流量200 mL·min^-1和反应液中NaOH与Na₂SO₃浓度均为0.10 mol·L^-1条件下,甲醇产率高达315.49 μmol·g^-1。并对稀土掺杂TiO₂催化剂光催化还原CO₂的机理进行了探究。