ZnS包覆 SiO2核壳和空腔结构纳米球制备研究

ZnS包覆SiO2三维核壳结构或空腔结构纳米球可用于光子晶体的组装.本实验采用层层自组装法,利用二氧化硅模板表面的静电作用吸附纳米晶粒子,生成纳米晶包覆层,制备核壳结构的SiO2@ZnS和SiO2@ZnS：Mn^2＋纳米球.控制氢氟酸对二氧化硅的蚀刻程度,制备了空腔型硫化锌纳米球.采用XRD、UV、PL、TEM、SEM、AFM等测试手段对核壳结构和空腔型硫化锌纳米球进行了表征.结果表明ZnS纳米晶包覆SiO2后,在其表面形成了包裹紧密、形貌规整、粒径均一的ZnS壳层;经5%氢氟酸蚀刻得到的空腔纳米球结构完好、厚度均匀.     

TiO_2纳米颗粒/纳米棒阵列复合薄膜的制备及其光电催化性能

以金属钛箔为钛源,采用双氧水和盐酸体系,通过水热法制备合成TiO2纳米棒阵列薄膜,并通过调节双氧水和盐酸的用量,调控TiO2纳米棒阵列薄膜的微观形貌和物相构成。结合溶剂挥发自组装法将TiO2纳米颗粒引入纳米棒阵列中,得到复合型TiO2光催化剂。以亚甲基蓝为模拟污染物,考察TiO2复合薄膜的光催化活性。通过扫描电镜(SEM)和X射线衍射(XRD)测试对TiO2复合薄膜的物相和表面形貌等进行了表征,并采用电化学交流阻抗法(EIS)分析其表面电荷转移特性。TiO2纳米颗粒/纳米棒阵列复合薄膜在光电协同条件下,展示出高的光电催化活性。     

TiO_2/尿素核壳纳米颗粒的制备及其电流变性能

在醇盐水解法制备TiO2颗粒的过程中加入尿素,制备TiO2/尿素核壳颗粒。采用SEM和TEM对颗粒的形貌进行表征,结果表明TiO2/尿素颗粒呈规则球形,粒径为400~500nm,具有良好的单分散性和完整的核壳结构;FT-IR分析表明,尿素成功包覆在TiO2颗粒表面;XRD分析表明,TiO2/尿素核壳颗粒呈无定形态。分别以TiO2/尿素核壳颗粒和纯TiO2颗粒为分散相制备同浓度的电流变液,性能测试结果表明,TiO2/尿素电流变液比纯TiO2电流变液具有更高的剪切屈服强度,且剪切应力在较宽的剪切速率范围内(1 000s-1)保持稳定。     

NiSi_x/Si/Ge核壳纳米棒阵列作为锂离子电池负极材料的电化学性能

硅是目前已知的理论比容量最高的锂离子电池负极材料,但是循环性能较差。本文通过射频磁控溅射的方法,成功合成出了NiSix/Si/Ge核壳纳米棒阵列,并通过扫描电子显微镜(SEM)和能量色散X射线光谱仪(EDX)对其形貌和成分进行了表征。将原位生长的NiSix/Si/Ge核壳纳米棒阵列直接作为工作电极,组装成纽扣半电池进行电化学和循环性能测试,NiSix/Si/Ge核壳纳米棒阵列的首次放电容量达到了2000mAhg-1左右,首次效率在70%左右,并且在100个循环以后仍保有初始可逆容量的30%以上。相比NiSix/Si纳米棒阵列,NiSix/Si/Ge核壳纳米棒阵列的循环性能明显得到了提升,说明锗的包覆对硅的锂离子电池性能改进起到了非常重要的作用。     

氮掺杂TiO_2纳米棒阵列的制备及光电化学性能研究

采用水热法在FTO玻璃上制备了TiO2纳米棒阵列,然后在氨气和氩气的混合气体中退火,得到氮掺杂TiO2纳米棒阵列。XRD及SEM测试结果表明产物均为金红石相,TiO2纳米棒阵列为倾斜生长在FTO衬底上,掺杂氮对产物的结构及形貌没有大的改变。XPS研究结果表明,N原子是以代替O原子的形式渗入TiO2纳米棒。通过光电化学研究,掺杂氮的TiO2纳米棒阵列比TiO2纳米棒阵列的光电流密度增加了66%。     

壳核结构纳米Fe包覆玻璃微珠复合材料的制备

以金属盐、柠檬酸和玻璃微珠等为原料,采用非均相沉淀-热还原法制备了纳米金属铁包覆空心玻璃微珠壳-核复合材料。采用SEM/EDS、XRD对包覆前后的复合微球进行了表征,分析了表面活性剂和加料速度对壳-核微球的形成、形貌和物相的影响。结果表明,在优化的工艺条件下,可以制备出晶粒尺寸约为50.2nm的纯铁均匀包覆的壳-核结构复合材料,包覆层显示出均匀、光滑和紧密的特点,包覆层Fe原子为体心立方结构。表面活性剂的加入提高了颗粒分散均匀性,促进了包覆层的形成。随着碳酸氢铵滴加速度的增大,引起均相沉淀的发生,在颗粒表面形成凸起。     

核壳结构TiO2光催化剂的制备和性能

统一尺寸、结构上有序包覆的核壳型复合材料,具有高折射率以及独特的电磁、光学和机械性质.结构上的独特性可能导致其在近红外和可见光区有完整的带隙,利用核与壳之间的相互作用,以及核对降解物的吸附等作用,可提高复合体的光催化性能.本文着重介绍核壳型TiO2的几种类型、特点及其性能,并提出其今后的发展方向.     

具有核-壳结构的金纳米包覆磁性纳米复合颗粒的研究进展

具有核-壳结构的金纳米包覆的磁性纳米粒子,既具有磁性纳米粒子的特点又增加了金纳米的表面化学性质,近年来受到研究人员的广泛关注。简要综述了近年来国内外制备2类核-壳结构的金包铁磁性纳米复合材料的研究进展及相关应用,并对其应用前景进行了展望。     

水热法制备核壳型纳米TiO2／Al2O3粉体的研究

通过一步水热制备TiO2/Al2O3核壳型纳米粉体,并且研究了pH值、水热温度和时间对核壳粉体的影响,最佳的反应条件为:制备前驱体的pH≈9.0,水热温度为260℃,水热保温时间为3.5h.产品的平均晶粒粒径小于20nm.通过XRD,TEM和SEM表征,核壳型纳米TiO2/Al2O3粉体包膜良好,且TiO2/Al2O3添加到水性乳胶漆后能提高其抗老化性能.     

核壳结构二氧化硅/磁性纳米粒子的制备及应用

核壳结构二氧化硅/磁性纳米粒子作为一种新型功能复合材料在生物医学方面有重要应用前景.综述了核壳结构二氧化硅/磁性纳米粒子的各种制备方法以及国内外在核壳结构二氧化硅/磁性纳米粒子制备方面的研究新进展,并对其在生物医学上的应用作了介绍.     

All-conjugated amphiphilic diblock copolymers for improving morphology and thermal stability of polymer/nanocrystals hybrid solar cells

Herein, the ability to optimize the morphology and photovoltaic performance of poly(3-hexylthiophene) (P3HT)/ZnO hybrid bulk-heterojunction solar cells via introducing all-conjugated amphiphilic P3HT-based block copolymer (BCP), poly(3-hexylthiophene)-block-poly(3-triethylene glycol-thiophene) (P3HT-b-P3TEGT), as polymeric additives is demonstrated. The results show that the addition of P3HT-b-P3TEGT additives can effectively improve the compatibility between P3HT and ZnO nanocrystals, increase the crystalline and ordered packing of P3HT chains, and form optimized hybrid nanomorphology with stable and intimate hybrid interface. The improvement is ascribed to the P3HT-b-P3TEGT at the P3HT/ZnO interface that has strong coordination interactions between the TEG side chains and the polar surface of ZnO nanoparticles. All of these are favor of the efficient exciton dissociation, charge separation and transport, thereby, contributing to the improvement of the efficiency and thermal stability of solar cells. These observations indicate that introducing all-conjugated amphiphilic BCP additives can be a promising and effective protocol for high-performance hybrid solar cells.     

TiO2纳米管的制备及应用研究

TiO2纳米管的制备与应用研究引起了科学家极大的兴趣，特别是TiO2纳米管在太阳能电池、光催化领域显示了广阔的应用前景。介绍了近年来TiO2纳米管的制备方法，并重点评述了TiO2纳米管在太阳能电池、光催化、光裂解水、气敏传感等方面的研究进展，展望了其发展方向。     

染料敏化太阳能电池MO／TiO2复合薄膜的制备与表征

用溶胶-凝胶法结合旋转镀膜法制备致密TiO2薄膜，采用丝网印刷技术制备多孔TiO2薄膜，采用液相沉积法制备ZnO／Ti02、MgO／TiO2复合薄膜。用x射线能谱仪、原子力显微镜、紫外-可见分光光度计对复合薄膜的化学组分、表面形貌、吸光性能等进行分析；组装电池，测定了电池性能。结果表明：ZnO／TiO2、MgO／TiO2复合薄膜具有较好的光电性能，染料敏化太阳能电池的短路电流、开路电压、填充因子、光电转换效率均得到提高。     

纳晶TiO2多孔薄膜电极的制备及其性能研究

用溶胶-凝胶法制备的TiO2胶体与乙基纤维素粘稠剂制备胶体溶液,通过丝网印刷技术制备纳晶TiO2多孔薄膜电极,对乙基纤维素的含量、TiO2的固含量和水热时间等制备工艺参数进行了研究.利用优化工艺条件后的纳晶TiO2多孔薄膜电极组装成染料敏化太阳能电池-TiO2/0.5molL LiI 0.05mol/L I2 0.5mol/L 4-叔丁基吡啶的三甲氧基丙腈溶液/Pt,在100mW/cm2光照条件下,光电转换效率可达到6.25%.     

Preparation and characterization of TiO2 anode film with spinodal phase separation structure in dye-sensitized solar cells

Low electronic transmission efficiency and high charge recombination are the existing problems of photoanode film in traditional dye sensitized solar cells (DSSCs). This paper put forward the photoanode TiO₂ films with spinodal phase separation structure (SPSS) and continuous TiO₂ skeleton which were triggered by the photopolymerization of organic monomers in a photomonomer-inorganic precursor system. The photoanode TiO₂ films fabricated by different precursor solution compositions and different coating layers were characterized mainly by scanning electron microscopy (SEM), photocatalysis and photoelectric performance test. The results indicated that, the as-prepared TiO₂ anode film with seven coating layers and heat treated at 500 °C showed higher photoelectric conversion efficiency at about 2% than that of other samples with less coating layers and lower heat treatment temperature. The film also showed excellent photocatalytic activity by using methylene blue (MB) dye as a model organic substrate under fluorescent lamp irradiation. It is suggested that the film with SPSS structure has the potential to improve the electronic transmission efficiency and reduce the carrier recombination due to its particular structure, higher surface area, and lack of bottleneck in electronic transmission. It is worth noting that the SPSS structure provides new ideas to develop new photoanode films and further improve the photoelectric conversion performance of the DSSC in future.     

聚苯乙烯和聚乙二醇对TiO2薄膜微观结构及DSSC性能的影响

用水热法制备了多孔TiO2光电薄膜;分析了聚苯乙烯和聚乙二醇对纳米TiO2晶体薄膜微观结构的影响;用紫外-可见-近红外分光光度计和场发射扫描电镜对纳米TiO2薄膜进行了表征;并对组装的染料敏化太阳能电池进行了光电性能测试,发现用聚苯乙烯处理后的TiO2薄膜提高了染料敏化太阳能电池(DSSC)的开路电压、短路电流密度、填充因子和光电转换效率.     

TiO2/壳聚糖纳米复合涂料制备及其在抗菌纸中的应用

以纳米TiO2、壳聚糖双胍盐酸盐为抗菌剂,加以胶黏剂羧基丁苯胶乳、分散剂六偏磷酸钠、消泡剂叔丁醇,制备了TiO2/壳聚糖纳米复合涂料,利用SEM、FT-IR对涂料的微观形貌和基本结构进行了表征。以表面涂布方式将TiO2/壳聚糖纳米复合涂料施涂于纸张表面,制得涂布抗菌纸,对涂布抗菌纸的微观结构及抗菌性能进行了研究。结果表明,经TiO2/壳聚糖纳米复合涂料涂布后,纸张具备较强的抗菌性能;而且,实验发现,随着涂料体系中壳聚糖组分的不断增加,涂布纸的抗菌性能逐渐提高。当纳米TiO2/壳聚糖的加入比例为1∶1时,双层涂布后的纸张对大肠杆菌和金黄色葡萄球菌的抗菌率分别达到86.55%和92.19%。     

Direct and seamless coupling of TiO2 nanotube photonic crystal to dye-sensitized solar cell: a single-step approach

A TiO(2) nanotube layer with a periodic structure is used as a photonic crystal to greatly enhance light harvesting in TiO(2) nanotube-based dye-sensitized solar cells. Such a tube-on-tube structure fabricated by a single-step approach facilitates good physical contact, easy electrolyte infiltration, and efficient charge transport. An increase of over 50% in power conversion efficiency is obtained in comparison to reference cells without a photonic crystal layer (under similar total thickness and dye loading).     

Preparation of Zr-doped mesoporous TiO2 particles and their applications in the novel working electrode of a dye-sensitized solar cell

This paper presents an implementation of our recent theory on the suspension of electron-hole recombination via electronic- and micro-structure optimization to study the influence of Zr-doping on the efficiency (η) of TiO₂-based dye-sensitized solar cells (DSSCs). We developed a four-layered working electrode, in which the size of particles increased from the bottom layer of TiO₂ (P-25) through three successive layers of Zr-doped TiO₂, which were calcined at 450, 600, and 850 °C respectively. The enhancement in open-circuit photovoltage (V_oc) and short-circuit photocurrent density (J_sc) can be attributed to the electronic- and micro-structures in the working electrode. The former is related to band bending, whereas the latter is related to light-scattering within multiple layers. Simulation results (FactSage) demonstrate that Zr doping in TiO₂ can suspend or delay the formation of oxygen vacancies and thereby reduce the number of electron scattering centers, which helps to suspend electron-hole recombination by strengthening Ti-O bonds. The proposed four-layered working electrode produced an 80.2% increase in η, compared with DSSCs using a TiO₂ (P-25) electrode. This study demonstrated a novel metal doping strategy for the manipulation of electronic structure and photoelectron conversion efficiency. The proposed methodology could also be used to guide the design of photo-catalysts in general.     

Preparation and characterization of P3HT:CuInSe2:TiO2 thin film for hybrid solar cell applications

Improved efficiency of hybrid Al/Ca/P3HT:CISe:TiO₂/PEDOT:PSS/ITO thin film solar cells was obtained by optimizing P3HT/CISe ratio. This study also investigated the effects of TiO₂ content in the P3HT:CISe active layer, and altering annealing temperature conditions. The optimum TiO₂ content and annealing temperature for solar cell efficiency is 25 wt.% and 150 °C, respectively. The optimal results for the open circuit voltages (V_OC), short-circuit current density (J_SC), fill factor (FF), and efficiency (η) of the prepared hybrid thin film solar cell were V_OC = 0.335 V, J_SC = 8.07 mA/cm², FF = 52.75, and η = 1.425.