CMC辅助纳米ZnO粒子的制备及表征

以离子型纤维素醚羧甲基纤维素(CMC)的水溶液为反应介质,制备[Zn4CO3(OH)6]CMC水凝胶,洗涤、干燥后经不同温度煅烧前驱物得到ZnO纳米粒子。通过XRD、SEM、TEM、TG-DSC及FT-IR等测试技术对产物的组成、粒径及形态进行表征,研究了CMC对前驱物及ZnO形态和尺寸的影响。结果表明,由于CMC加入对煅烧前驱物产生的空间位阻作用,所制得纳米ZnO粒子粒度分布均匀、分散性好、不易团聚、粒子的平均粒径<20 nm。利用UV-V is测试了纳米ZnO的光吸收性能,所得的纳米ZnO在200~400 nm具有较强的吸收性。     

Luminescence Property and Synthesis of Sulfur-doped ZnO Nanowires by Electrochemical Deposition

"Sulfur-doped zinc oxide (ZnO) nanowires were successfully synthesized by an electric field-assisted electrochemical deposition in porous anodized aluminum oxide template at room temperature. The structure, morphology, chemical composition and photoluminescence properties of the as-synthesized ZnO:S nanostructures were investigated. X-ray diffraction and the selected area electron diffraction results reveal that the as-ynthesized products are single phase with hexagonal wurtzite structure with a highly preferential orientation in the (101) direction. Transmission electron microscopy observations indicate that the nanowires are niform with an average diameter of 70 nm and length up to several tens of micrometers. X-ray photoelectron pectroscopy further reveals the presence of S in the ZnO nanowires. Room-temperature photoluminescences observed in the sulfur-doped ZnO nanowires which exhibits strong near-band-edge ultraviolet peaks at 378 and 392 nm and weak green emissions at 533 and 507 nm. A blue emission at 456 nm and violet emissions at around 406, 420, and 434 nm were also observed in the PL spectrum for the as-synthesized ZnO:S nanowires. The PL spectrum shows that S-doping had an obvious effect on the luminescence property of typical ZnO nanowires."     

Preparation and Photoluminescence of ZnO Comb-Like Structure and Nanorod Arrays

A large quantity of Zinc oxide (ZnO) comb-like structure and high-density well-aligned ZnO nanorod arrays were prepared on silicon substrate via thermal evaporation process without any catalyst. The morphology, growth mechanism, and optical properties of the both structures were investigated using XRD, SEM, TEM and PL. The resulting comb-teeth, with a diameter about 20 nm, growing along the 0001 direction have a well-defined epitaxial relationship with the comb ribbon. The ZnO nanorod arrays have a diameter about 200 nm and length up to several micrometers growing approximately vertical to the Si substrate. A ZnO film was obtained before the nanorods growth. A growth model is proposed for interpreting the growth mechanism of comb-like zigzag-notch nanostructure. Room temperature photoluminescence measurements under excitation wavelength of 325 nm showed that the ZnO comb-like nanostructure has a weak UV emission at around 384 nm and a strong green emission around 491 nm, which correspond to a near band-edge transition and the singly ionized oxygen vacancy, respectively. In contrast, a strong and sharp UV peak and a weak green peak was obtained from the ZnO nanorod arrays.     

Supersaturation Control Growth of Nanoparticle ZnO and Size Distribution Control

"Nanoparticle ZnO was synthesized in non-aqueous medium. UV adsorption spectra were measured and effective mass model was used to calculate particle size in situ. A technique method named as supersaturation control growth was developed, which dealt with addition of nanoparticle suspension with small size to another suspension with big size. As a result, those small particles completely dissolved and those big ones totally grew because of dissolution degree difference between small particles and the big ones. The particle number of big particle suspension kept being a constant and the growth rate was much higher than Ostwald ripening. Main characteristic of this technique is that size distribution of nanoparticles can be narrowed provided original size difference of two suspension is big enough and original size distribution is not too broad."     

Synthesis and photoluminescence study on ZnO nano-particles

A new technique, namely low pressure sputtering, has been developed to fabricate Zn nanoparticles, with a subsequent oxidation to synthesize ZnO nanoparticles in the ambient atmosphere at 500$\,^{\circ}$C. The synthesized ZnO nanoparticle has a size of 6--8~nm with a preferred orientation of $c$-axis. The produced ZnO nanoparticles have a good UV photoluminescence (PL) emission energy of 3.349 eV with a significant enhancement of donor--acceptor pair emission located at 3.305 eV which implies a number of donor and acceptor bounded excitons existing in the synthesized ZnO nano particles. The near band edge PL emission of the fabricated ZnO is dominated by the bounded excitons at 10~K.     

自然光下ZnO/共轭高分子复合微粒的催化性能

自然光下ZnO/共轭高分子复合微粒的催化性能;ZnO; 共轭高分子; 催化; 自然光     

Effects of ZnO Buffer Layer Thickness on Properties of MgxZn1-xO Thin Films Deposited by MOCVD

High-quality MgxZn1-xO thin films were grown on sapphire（0001 ） substrates with a ZnO buffer layer of different thicknesses by means of metal-organic chemical vapor deposition. Diethyl zinc, bis-cyclopentadienyl-Mg and oxygen were used as the precursor materials. The crystalline quality, surface morphologies and optical properties of the Mg, Zn1-xO films were investigated by X-ray diffraction, atomic force microscopy and photoluminescence spectrometry. It was shown that the quality of the MgxZn1-xO thin films depends on the thickness of the ZnO buffer layer and an Mg, Zn1-xO thin film with a ZnO buffer layer whose thickness was 20 nm exhibited the best crystal-quality, optical properties and a flat and dense surface.     

纳米ZnO改性锌电极的性能

纳米ZnO改性锌电极的性能;纳米ZnO;锌电极;循环可逆性;放电容量     

水热法制备高度取向的氧化锌纳米棒阵列

氧化锌的激子结合能(60meV)及光增益系数(300cm^-1)比GaN的(25meV,100cm^-1)还高,这一特点使它成为紫外半导体激光发射材料的研究热点。最近,Yang等成功地观测到规则的ZnO纳米线阵列的激光发射现象,更加激起了人们合成一维高度有序ZnO纳米结构的热情,由于一维ZnO     

活性粒子吸附对ZnO纳米粒子表面光伏特性的影响

作为一种传统的半导体,氧化锌在压电陶瓷、光电化学、光催化、发光器件以及气体传感器等方面具有广阔的应用前景,特别是氧化锌纳米粒子,由于其比表面积大、表面活性较高和对周围环境的敏感性,使其成为传感器研究领域中最有前途的材料,有关生物氧传感器和激光器的光电功能特性以及其能带结构的研究已有报道,