铟镓共掺杂对n-ZnO纳米棒/p-GaN异质结生长行为和光电性能的影响

利用低温水热法在p-GaN薄膜上生长了铟(In)和镓(Ga)共掺杂的ZnO纳米棒。X射线衍射(XRD)、X射线光电子能谱(XPS)和X射线能量色谱仪(EDS)结果表明,In和Ga已固溶到ZnO晶格中。扫描电子显微镜(SEM)结果表明, ZnO纳米棒具有良好的c轴取向性,随着In和Ga共掺杂浓度的增加,纳米棒的直径减小,密度增加。XRD结果表明,In和Ga共掺杂引起ZnO晶格常数增大,导致(002)衍射峰向低角度方向偏移。同时,ZnO的光学性质受到In和Ga共掺杂的影响。与纯ZnO相比, 共掺杂ZnO纳米棒的紫外发射峰都出现轻微红移,这是表面共振和带隙重整效应综合作用的结果。I-V特性曲线表明,随着In和Ga共掺杂浓度的增加,n-ZnO纳米棒/p-GaN异质结具有更好的导电性。     

In-situ preparation and electrochromic properties of TiO2/PTPA-HTAN core-shell nanocomposite film

A new star-shaped structure conjugated microporous polymers, poly (2,8,14-tri[4-diphenyl-benzene]-hexaazatrinaphthylene) (PTPA-HATN), was designed and in-situ electrochemically polymerized on the surfaces of FTO electrodes with a directional alignment TiO₂ nanorod array to obtain TiO₂/PTPA-HATN core-shell nanocomposite films. Compared with the PTPA-HATN film, the TiO₂/PTPA-HATN composite film exhibits higher optical contrast and faster response time, with contrast of 57% at 783 nm, coloring time of 3.62 s and discoloring time of 2.55 s (43%, 4.63 s and 4.77 s for PTPA-HATN film, respectively). After 400 cycles, the contrast of nanocomposite film decreased by 28%, while the PTPA-HATN film basically lost its electrochromic properties. A simple three-layer EC prototype device based on TiO₂/PTPA-HATN nanocomposite film constructed with hydrogel electrolyte clearly shows color changes at different voltages. On the one hand, the formation of core-shell porous nanostructure of TiO₂/PTPA-HATN composite film provides a larger ion doping/de-doping interface, shortening the average diffusion length of ions. On the other hand, the large indented polymer-nanorods contact interface makes it difficult for the polymer to detach from the electrode, thus significantly improving the cyclic stability of the composite film.     

Facile preparation of superhydrophobic nanorod surfaces through ion-beam irradiation

Obtaining superhydrophobic surfaces for their application in electronics and flexible wearable devices remains a significant challenge. Most previously reported methods for obtaining superhydrophobic surfaces involve complex and expensive preparation techniques and thus cannot be used for practical applications. Ion-beam irradiation is a simple and promising method for fabricating superhydrophobic nanostructures on large areas at a low cost. Ion-beam irradiation using argon and oxygen gases was used to prepare silica nanorod structures on glass substrates. This study is not just a modification of the surface of nanoparticles, but a change in nanoparticle shape. The nanorods were subsequently treated with perfluorooctyltriethoxysilane to obtain superhydrophobicity. The surface of the silica nanorods exhibited a static water contact angle of 153°, indicating superhydrophobicity. The combination of rough structures of silica nanorods and low surface energy resulted in superhydrophobicity. The surface properties were evaluated in detail using Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The proposed method is facile, inexpensive, and can be used for the large-scale production of nanorod structures for potential industrial applications.     

ZnO纳米棒阵列基-芴类共轭聚合物膜的制备及对TNT的检测评价

将共轭芴类荧光聚合物涂覆在纳米Zn O棒阵列上,制成荧光传感膜检测痕量TNT。通过水热法生长的Zn O纳米棒阵列具有较好的取向性,作为衬底可有效增大荧光膜荧光强度,同时,Zn O纳米棒阵列的高比表面积可提高膜对TNT气体的响应效率,使20s内的荧光猝灭率可达72%。     

基于纳米Nb_2O_5/石墨烯复合材料的增强效应电化学测定绿原酸

制备了Nb_2O_5/石墨烯修饰玻碳电极(Nb_2O_5/RGO/GCE),建立了一种简便、灵敏检测绿原酸的电化学方法。用氧化石墨烯(GO)和五氯化铌(Nb Cl5)一步溶剂热法制备Nb_2O_5/RGO复合材料,并用扫描电子显微镜(SEM)对其进行形貌表征。采用循环伏安法(CV)和方波伏安法(SWV)研究了绿原酸在Nb_2O_5/RGO/GCE上的电化学行为。结果发现,Nb_2O_5/RGO复合材料能显著增强绿原酸的电化学活性。对实验条件(如pH值、扫描速率与富集时间等)进行了优化。在最佳条件下,绿原酸的氧化峰电流与浓度在5.0×10~(-7)~1.2×10~(-5)mol/L范围内呈良好的线性关系,检出限为2.0×10~(-7)mol/L。采用修饰电极测定各种药物中绿原酸的含量,得到加标回收率为96.6%~101.5%。该方法具有良好的灵敏度和稳定性,已成功应用于药物中绿原酸含量的测定。     

Comparison of two types of vertically aligned ZnO NRs for highly efficient polymer solar cells

Vertically aligned ZnO nanorods (NR) are prepared by two different syntheses methods and applied on polymer solar cells (PSCs). The ZnO electrodes work as the electron transport layer with the P3HT:PCBM blend acting as the active material. Several organic blend solution conditions are optimized: concentration, solvent, and deposition speed. The effect of different NR electrode morphologies is analyzed on the solar cell performance and characterized by current–voltage curves and IPCE analyses. The photovoltaic performance of the solar cells was observed to be influenced by many factors, among them infiltration of the organic P3HT:PCBM blend within the ZnO NR layer. The infiltration of the active layer was monitored by cross section SEM and energy dispersive X-ray spectroscopy analyses. Our results show that higher power conversion efficiencies are achieved when shorter NRs lengths are applied. The best power conversion efficiency obtained was 2.0% for a 400 nm ZnO NR electrode. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

导电聚苯胺线膜修饰ZnO纳米棒阵列的可控制备及其紫外探测性能

基于p-n结的光生伏特效应可构筑性能优异的UV探测器,本文采用水热法可控制备竖直排列的氧化锌纳米棒阵列(n型ZnO-NRs),利用原位聚合法在ZnO-NRs表面上修饰p型聚苯胺线膜(PANI-NWs),再组装成ZnO-NRs与ZnO-NRs/PANI-NWs紫外探测器。通过扫描电镜(SEM)、X射线衍射仪(XRD)、紫外可见漫反射(UV-Vis)光谱表征样品的形貌、结构与光学性质。并通过电化学工作站测定电流-时间(I-t)和电流电压(I-V)曲线,表征其光响应性能。结果表明,制备的ZnO-NRs/PANI-NWs材料阵列排列整齐,界面接触良好,孔隙均匀。ZnO-NRs/PANI-NWs探测器在检测365 nm紫外光时,光电流为2.73×10^-4 A;检测254 nm紫外光时,光电流为1.44×10^-4 A。其光电流为ZnO-NRs探测器的4~10倍,ZnO-NRs和PANI-NWs之间形成的p-n结增强了光电导。用ZnO-NRs/PANI-NWs材料组装成的UV探测器体现出稳定性好,响应速度快,恢复时间短,电流增益高等优点,为开发高性能紫外光电探测器提供数据支撑。     

Synthesis of Au nanorods via autocatalytic growth of Au seeds formed by sonochemical reduction of Au(I): Relation between formation rate and characteristic of Au nanorods

The sonochemical formation of Au seeds and their autocatalytic growth to Au nanorods were investigated in a one-pot as a function of concentration of HAuCl₄, AgNO₃, and ascorbic acid (AA). The effects of ultrasonic power and irradiation time were also investigated. In addition, the formation rate of Au nanorods was analyzed by monitoring the extinction at 400 nm by UV–Vis spectroscopy and compared with the growth behavior of Au seeds to nanorods. Most of the reaction conditions affected the yield, size, and shape of Au nanorods formed. It was confirmed that the concentration balance between HAuCl₄ and AA was important to proceed the formation of Au seeds and nanorods effectively. The formation rate became faster with increasing AA concentration and dog-bone shaped nanorods were formed at high AA concentration. It was also confirmed a unique phenomenon that the shape of Au nanorods changed even after the completion of the reduction of Au(I) in the case of short-time ultrasonic irradiation for Au seed formation.     

Synthesis of 15P-Conjugated PPy-modified Gold Nanoparticles and Their Application to Photothermal Therapy of Ovarian Cancer

In this work, we synthesized the polypyrrole（PPy） modified gold nanoparticles and demonstrated their negligible cytotoxicity in vitro. These nanoparticles have also been demonstrated to efficiently ablate different kinds of tumor cells in vitro under the irradiation of the near-infrared laser. When the PPy modified gold nanoparticles were conjugated with the tumor-targeted molecule of 15P（sequence： SHSWHWLPNLRHYAS）, these conjugates displayed hyperthermia effects on the human ovarian cancer cell line SK-OV-3 cells in vitro under the irradiation of near-infrared laser, showing great tumor-targeted treatment efficiency. To determine the potential hyperthermia effect of PPy modified gold nanoparticles or 15P-conjugate on tumor cells in vivo, the SK-OV-3 cells were used to induce the subcutaneous tumor-bearing nude mice. The significant inhibition effects of near-infrared laser mediated PPy modified gold nanoparticles or 15P-conjugate on the tumor growth were observed. These composite results suggest that the 15P-conjugated PPy modified gold nanoparticles exhibit great biocompatibility, particularly tumor-targeted effect and the effective photothermal ablation of tumor cells, which warrants the potential therapeutic value of this conjugate for further application to the in vivo localized tumor therapy.     

Chemisorption assembly of Au nanorods on mercaptosilanized glass substrate for label-free nanoplasmon biochip

The fabrication of a localized surface plasmon resonance nanosensor in a chip based format that utilizes Au nanorods (GNRs) as the optical transducer were systematically studied. (3-mercaptopropyl)trimethoxysilane (MPTMS) modified glass substrate offers GNR deposition with maximal sensitivity to local refractive index changes, which subsequently results in better optical recognition of receptor–analyte binding. Kinetics governing the mass transport and chemisorption of nanorods from bulk to solid surface can be dynamically controlled in a predictable fashion. We demonstrate that slight aggregation induced by a low ionic strength (5 mM NaCl) can facilitate the nanorod assembly to result in a dense, well-distributed surface monolayer. In high ionic media (e.g. 40–80 mM), anions present electrostatically bind with the positively charged cetyltrimethylammonium bromide (CTAB) surrounding nanorod surfaces, thereby leading to instability with heavy aggregation in solution. However, once chemically bound on silanized substrates, the nanorods exhibit excellent stability in physiological buffer where high amount of ionic species are present. The fundamental study is followed by demonstration of a practical application of the fabricated biochip in label-free detection based on GNR wavelength shift of the longitudinal palsmon maxima as the optical signature of human IgG model detection.