异质结型BaTiO3/TiO2复合纳米纤维的制备及光催化性能

以静电纺丝技术制备的TiO₂纳米纤维为模板和反应物, 采用水热法原位合成了具有异质结构的BaTiO₃/TiO₂复合纳米纤维。利用X射线衍射(XRD)、扫描电镜(SEM) 和高分辨透射电镜(HRTEM)等分析测试手段对样品的结构和形貌进行表征。结果表明: BaTiO₃纳米微粒均匀地生长在TiO₂纳米纤维表面, 制备了异质结型BaTiO₃/TiO₂复合纳米纤维。材料的光催化性能利用罗丹明B和苯酚的脱色降解反应测试。BaTiO₃/TiO₂复合纳米纤维材料, 在紫外光照射下, 光催化降解活性较纯锐钛矿TiO₂纳米纤维有明显提高, 罗丹明B和苯酚在该复合纳米纤维材料上的光催化降解反应遵循一级反应动力学。且易于分离、回收和再利用, 循环使用5次, 罗丹明B的脱色率仍保持在96%以上。     

不同合成过程对溶胶-凝胶法制备的ZnO/Ag纳米复合材料光催化性能的影响

以乙酸锌、硝酸银为前驱体,二乙醇胺作为稳定剂,利用溶胶-凝胶法分别采用一步法和两步法制备得到ZnO以及ZnO/Ag纳米复合粉体。所有ZnO/Ag复合物中Ag的含量均为3%(摩尔分数)。对所制备样品的结构和光学性质通过XRD、SEM、TEM、XPS、PL、UV-vis进行了表征,进而以甲基橙为模拟污染物进行了光催化测试。结果表明,不同方法制备得到的ZnO/Ag纳米粉体晶粒均匀,无明显团聚现象,面心立方结构的金属Ag吸附在纤锌矿结构的ZnO表面形成异质结。与纯ZnO相比,掺Ag极大地改善了样品在紫外光下的光催化活性。对不同合成工艺的比较表明,用溶胶-凝胶一步法制备的ZnO/Ag复合物的光催化活性最高,经紫外光照射70min可完全降解甲基橙。     

ZnO/In2O3纳米异质结的合成及其光催化性能的研究

通过热水解法成功制备出了形貌均一的ZnO/In₂O₃异质结光催化材料, 采用场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)以及透射电子显微镜(TEM)对样品的形貌及结构进行表征。结果表明: ZnO/In₂O₃异质结是由直径约200~300 nm、厚度约40~60 nm的六边形纳米片镶嵌着In₂O₃纳米小颗粒组成。对比纯ZnO、纯In₂O₃和该光催化材料对罗丹明B(RhB)的可见光降解效率, 发现ZnO/In₂O₃异质结光催化材料对RhB具有较高的光催化效率, 其原因是窄带系半导体In₂O₃能够有效地吸收可见光, 当ZnO与In₂O₃ 形成异质结时, In₂O₃能带上被可见光激发的电子会迁移到ZnO的导带上, 而光激发的空穴仍保留在In₂O₃价带, 这样有助于光生电子和空穴的分离, 降低其复合几率, 从而有效地提高了ZnO的光催化效率。     

CeO2/ZnO复合光催化剂制备及其可见光催化性能

采用微波超声法,以ZnO为基体原位生长CeO₂晶体,得到CeO₂/ZnO复合光催化剂。利用XRD、SEM、TEM、PL、UV-Vis DRS等方法对制备的材料进行表征,并通过可见光降解AF对样品的光催化性能进行评价。结果表明,ZnO为纳米片互相穿插形成的花形球状结构,其表面附着有纳米CeO₂颗粒,分散性较好。ZnO和CeO₂的摩尔比为20∶1的CeO₂/ZnO复合光催化剂在可见光下表现出良好的光催化活性,光照90 min后对AF的光降解率达到96.44%,较纯相ZnO和CeO₂有显著提高。CeO₂/ZnO的稳定性较好,6次使用后对AF的光降解率仍达到93.53%。机制研究发现,·O₂?是光催化降解AF过程中的主要活性物种。      

CuO/ZnO复合纳米树阵列的制备及光学特性

通过热氧化法在铜基板上制备CuO纳米线,采用凝胶法制备ZnO/CuO复合纳米树阵列。通过扫描电镜(SEM)、X射线衍射(XRD)、光致发射光谱对样品结构、形貌、光学特性进行表征。结果表明,CuO/ZnO纳米树形貌规整完美,在CuO纳米线上二次生长的ZnO纳米棒具有各向晶体生长性质,CuO/ZnO复合纳米树在可见光区域出现了优越的发光性能;以甲基橙为模拟污染物,通过光催化测试表明,CuO/ZnO复合纳米树还具有卓越的光催化性能。     

薄片状C60/ZnO纳米复合材料的制备及其光催化性能

首先通过简单沉淀法制备了薄片状纳米ZnO,再利用化学吸附作用将C60与ZnO复合得到C60/ZnO纳米复合材料。采用XRD、SEM、XPS、Ra-man、DRS、PL等技术对样品进行表征,紫外光下以亚甲基蓝(MB)作为探针分子,研究C60/ZnO纳米复合材料的光催化活性。结果表明,C60/ZnO纳米复合材料的光催化活性优于单纯的纳米ZnO,且1%(质量分数)C60/ZnO的光催化活性最高,这是由于C60具有良好的接受和传导电子的作用,抑制了光生电子和空穴的复合,从而提高了光催化效率。     

Ce/ZnO纳米复合抗菌剂的制备及其性能研究

以纳米氧化锌(ZnO)为载体,采用稀土离子掺杂的方法制备了Ce/ZnO纳米复合抗菌剂。通过TEM、XRD等技术对样品进行表征,结果表明:制备的Ce/ZnO复合粉体是一种纳米复合抗菌剂,粒径在20nm左右,并且铈以CeO2的化学态存在于Ce/ZnO复合粉体表面,在ZnO的位置上进行了有效掺杂。掺杂稀土铈有效的提高了纳米ZnO的光催化性能以及抗菌效果。     

ZnO复合石墨相氮化碳纳米片的制备及其光催化性能研究

为了提高石墨相氮化碳光催化性能,本文以尿素、硫脲、醋酸锌为前驱体,通过氧化热剥离与共混煅烧法分别制备g-C₃N₄纳米片和ZnO/g-C₃N₄异质结复合材料,并采用TEM、FTIR、XRD、UV-Vis DRS、BET等表征手段对制备的催化剂进行结构表征。以罗丹明、大肠杆菌为探针,考察了催化剂的光催化降解性能和抑菌活性。结果表明：以尿素和硫脲为前驱体,经过氧化热剥离处理后能得到的g-C₃N₄ 2D纳米片,其比表面积更大、光催化性能更加优异,且其对罗丹明的降解率较未剥离的g-C₃N₄提高了21.2%。在40 min氙灯照射下,纯g-C₃N₄并未表现出良好的抑菌性能,而通过ZnO复合制备的ZnO/g-C₃N₄异质结复合材料,在光催化降解率和抑菌活性方面均有很大提高,其中复合20%ZnO制得的ZnO异质结复合材料表现出最佳的光催化性能...     

环境友好型塑料用改性ZnO添加剂的光催化性能研究

以纳米ZnO和AgNO3溶液为原料,采用掺杂的方法制备了改性的塑料用ZnO添加剂,通过其光催化降解亚甲基蓝的效果评价了样品的光催化性能。实验结果表明,当银的掺杂量为2.8%,光催化剂添加浓度是0.8g/L时,此时Ag/ZnO复合粉体对亚甲基蓝的光催化降解效果最好。制备的Ag/ZnO复合粉体在紫外光区和可见光区都有较强的吸收,且吸收峰波长和Ag与纳米ZnO相比都出现了一定程度的红移。掺杂银显著提高了纳米ZnO的光催化性能     

水热反应温度对PMMA/TiO_2复合纳米纤维膜的形貌和性能的影响

利用静电纺丝技术成功制备了聚甲基丙烯酸甲酯/钛酸四正丁酯(PMMA/TBT)复合纳米纤维膜,通过水热法处理得到了PMMA/TiO_2柔性复合纳米纤维膜。通过傅立叶红外光谱(FTIR)、热失重分析法(TGA)、X射线衍射法(XRD)等手段对PMMA/TiO_2复合纳米纤维膜进行了表征,借助扫描电子显微镜(SEM)、全自动比表面积及孔隙分析仪(BET)对该材料的形貌结构、孔隙结构进行分析,最后探讨了所制备的纳米纤维膜的光催化降解能力,综合分析了反应温度对水热法制备PMMA/TiO_2复合纳米纤维膜的形貌、结构及性能的影响。结果表明:水热反应温度为200℃时,得到的PMMA/TiO_2复合纳米纤维膜中TiO_2晶型为纯锐钛矿型,且晶体生长速率较快,比表面积较大,对污染物亚甲基蓝的脱色效率最高,可达98.93%。     

Electrospun nanofibers of p-type NiO/n-type ZnO heterojunctions with enhanced photocatalytic activity

One-dimensional electrospun nanofibers of p-type NiO/n-type ZnO heterojunctions with different molar ratios of Ni to Zn were successfully synthesized using a facile electrospinning technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance (DR) spectroscopy, resonant Raman spectroscopy, photoluminescence (PL) spectroscopy, and surface photovoltage spectroscopy (SPS) were used to characterize the as-synthesized nanofibers. The results indicated that the p-n heterojunctions formed between the cubic structure NiO and hexangular structure ZnO in the NiO/ZnO nanofibers. Furthermore, the photocatalytic activity of the as-electrospun NiO/ZnO nanofibers for the degradation of rhodamine B (RB) was much higher than that of electrospun NiO and ZnO nanofibers, which could be ascribed to the formation of p-n heterojunctions in the NiO/ZnO nanofibers. In particular, the p-type NiO/n-type ZnO heterojunction nanofibers with the original Ni/Zn molar ratio of 1 exhibited the best catalytic activity, which might be attributed to their high separation efficiency of photogenerated electrons and holes. Notably, the electrospun nanofibers of p-type NiO/n-type ZnO heterojunctions could be easily recycled without a decrease of the photocatalytic activity due to their one-dimensional nanostructural property.     

Preparation of Au nanoparticle-decorated ZnO/NiO heterostructure via nonsolvent method for high-performance photocatalysis

In this paper, we present a novel physical (or nonsolvent) route to fabricate a kind of Au/ZnO/NiO heterostructure photocatalytic composite. That is, a Zn layer upon Ni foam substrate is prepared by pulse electrodeposition, then the ZnO nanoneedle/NiO heterostructural composite is obtained via thermal oxidation, and at last, the composite is modified with the dispersively deposited Au nanoparticles (Au NPs) by ion sputtering. The surface plasmon resonance effect of the Au NPs significantly enhances the light absorption. Meanwhile, the Au NPs form a Schottky barrier with ZnO nanoneedles and further inhibit the recombination of photogenerated electron–hole pairs. In addition, due to the nonsolvent conditions, the introduction of impurities is avoided, and thus it shows strong photocatalytic stability. The experimental results reveal that, the optimized Au/ZnO/NiO composite exhibits up to two times photocatalytic performance on RB degradation and higher stability than that of regular ZnO/NiO composite. The present experimental strategy can also be used for other noble metals, and it is expected to have important application prospects in the fields of environmental purification, solar cells, hydrogen generation, etc.     

γ-Bi2O3/TiO2复合纤维的制备及光催化性能

采用静电纺丝技术与溶剂热法相结合制备了γ-Bi2O3/TiO2复合纤维光催化材料.利用X射线衍射(XRD)、扫描电镜(SEM)、电子能谱(EDS)、透射电镜(TEM)、高分辨透射电镜(HRTEM)和紫外–可见吸收光谱(UV-Vis)等分析测试手段对材料进行了表征,并以罗丹明B(RB)的脱色降解为模式反应,考察了材料的可见光催化性能.结果表明:γ-Bi2O3纳米片均匀地生长在TiO2纤维上,形成了具有异质结构的γ-Bi2O3/TiO2复合纤维光催化材料,其光谱响应范围拓宽至可见光区,有利于TiO2光生电子和空穴的分离,增强了体系的量子效率.与纯TiO2纤维相比可见光催化活性明显提高,对RB的脱色率达87.8%.     

Fabrication of TiO2/ZnO composite nanofibers by electrospinning and their photocatalytic property

TiO₂/ZnO composite nanofibers with diameters in the range of 85–200 nm were fabricated via the electrospinning technique using zinc acetate and titanium tetra-isopropoxide as precursors, cellulose acetate as the fiber template, and N,N-dimethylformamide/acetone 1:2 (v/v) mixtures as the co-solvent. After treated with 0.1 mol/L NaOH aqueous solution, TiO₂/zinc acetate/cellulose acetate composite nanofibers were transformed into TiO₂/Zn(OH)₂/cellulose composite nanofibers. TiO₂/ZnO composite nanofibers were obtained by calcinating the hydrolyzed composite fibers at 500 and 700 °C for 5 h. The structure and morphology of composite nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. With the blending of ZnO into TiO₂, a new crystallite ZnTiO₃ was formed in addition to the ZnO and TiO₂ crystallites, and the ultraviolet light absorption efficiency was enhanced according to the UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of TiO₂/ZnO composite nanofibers toward the decomposition of Rhodamine B and phenol was investigated. Almost 100% Rhodamine B and 85% phenol were decomposed in the presence of TiO₂/ZnO composite nanofibers under mild conditions. The results demonstrated that the blending of ZnO in the TiO₂/ZnO composite nanofibers increased the photocatalytic efficiency. The optimum ZnO content in the TiO₂/ZnO composite nanofibers was 15.76 wt% to reach the most efficient photocatalytic activity. A schematic diagram of photocatalytic mechanism of TiO₂/ZnO composite nanofibers was also presented.     

CdS/ZnO复合颗粒的制备与电致发光性能

以sol-gel法制备了ZnO前驱体,并通过水热反应得到了CdS/ZnO复合颗粒.采用红外光谱(IR)、X射线衍射(XRD)、扫描电镜(SEM)表征其结构、组成及形貌,并对其电致发光(EL)特性进行表征.结果表明CdS纳米晶生长在ZnO基体上;EL谱表明没有煅烧的CdS/ZnO复合颗粒表现为CdS的激子发射,发光强度较纯CdS有了明显的提高;而煅烧后的CdS/ZnO复合颗粒则表现为ZnO的缺陷发射,发光谱的半高宽较纯ZnO有所减小.     

锂离子电池用氧化锌/螺旋纳米碳纤维复合负极材料的制备及性能研究

以二水乙酸锌、一缩二乙二醇为原料,通过溶胶-凝胶法制备出氧化锌/螺旋纳米碳纤维(ZnO/HCNFs)复合材料。使用X射线衍射仪(XRD)、热重分析仪(TG)和扫描电子显微镜(SEM)等表征手段研究了ZnO/HCNFs复合材料的形貌结构,通过恒流充放电测试仪对材料的电化学性能进行测试。结果表明:ZnO颗粒均匀负载于HCNFs表面,粒径约为20~50nm。ZnO/HCNFs复合材料在200mA/g的电流密度下,其首次充放电比容量分别达到977mAh/g与788mAh/g,库仑效率为81%,经过100次循环以后,容量仍保持在501mAh/g,电化学性能较优异。     

SnO2/NiO复合半导体纳米纤维的制备及气敏性能研究

采用静电纺丝技术结合化学沉淀法和高温煅烧处理,制备了具有不同Sn含量的SnO2/NiO复合半导体纳米纤维.采用扫描电子显微镜(SEM),X射线衍射仪(XRD)和能量色散X射线光谱仪(EDS)对样品的形貌,结构以及各元素含量进行表征.以乙醇为目标气体,探究SnO2/NiO纳米纤维的气体传感性质,以及Sn含量对复合纳米纤维...     

Synthesis and Characterization of Cu Nanoparticles Embedded in PAN/β-Cyclodextrin (β-CD) Composite Nanofiber Films

In the study, PAN/β-cyclodextrin (β-CD) one dimensional composite nanofibers were synthesized with sol-gel method and electrospinning, and then, we dipped the composite nanofibers into NaBH₄ aqueous solution acted as reducing agent to fabricate PAN/β-CD/Cu composite nanofibers. We got the PAN/β-CD/Cu composite nanofibers with different concentration of β-CD, and Cu nanoparticles formed on its surface. The final products were characterized using scanning electronic microscope (SEM), fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM). The results of characterization showed that the Cu nanoparticles with small size were well-distributed on the composite nanofibers.     

High photocatalytic activity of ZnO-carbon nanofiber heteroarchitectures

One-dimensional ZnO-carbon nanofibers (CNFs) heteroarchitectures with high photocatalytic activity have been successfully obtained by a simple combination of electrospinning technique and hydrothermal process. The as-obtained products were characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and IR spectrum. The results revealed that the secondary ZnO nanostructures were successfully grown on the primary CNFs substrates without aggregation. And, the coverage density of ZnO nanoparticles coating on the surface of the CNFs could be controlled by simply adjusting the mass ratio of zinc acetate to CNFs in the precursor during the hydrothermal process for the fabrication of ZnO-CNFs heterostructures. The obtained ZnO-CNFs heteroarchitectures showed high photocatalytic property to degrade rhodamine B (RB) because of the formation of heteroarchitectures, which might improve the separation of photogenerated electrons and holes. Moreover, the ZnO-CNFs heteroarchitectures could be easily recycled without the decrease in photocatalytic activity due to their one-dimensional nanostructural property.