Nano-composite ZrO2/Au film electrode for voltammetric detection of parathion

This work describes the fabrication of ZrO₂/Au nano-composite films and its application for voltammetric detection of organophosphate pesticides. The nano-composite ZrO₂/Au film was prepared through a combination of sol–gel procedure and electroless plating that can be carried out in a general chemistry lab with no need for special facilities and reagents. The sensing performance of the ZrO₂/Au nano-composite film electrode toward parathion was studied with square wave voltammetry. The nano-ZrO₂ showed a strong affinity toward the phosphate group on parathion molecules, which provides sensitivity and selectivity of the sensing film. A linear relationship was obtained between the peak currents and the concentration of parathion, with a detection limit for standard samples of 3 ng/ml. In addition, interference studies showed that structurally similar compounds without phosphate groups would not interfere with the response toward parathion of the film electrode.     

Fabrication of patterned single-walled carbon nanotube films using electrophoretic deposition

Thin films of chemically functionalized single-walled carbon nanotubes (SWNTs) were fabricated by using a direct current (dc) electrophoretic deposition method. SWNTs were shortened and then functionalized with acid chloride group to combine with the amine group-terminated gold substrate. Silica nanospheres with a diameter of about 190nm were arrayed on gold substrate to pattern a thin SWNT film. Periodically patterned SWNT film was eventually produced and would be used in potential applications like electron emitters and large surface area electrodes.     

高熵合金氮化物薄膜的研究进展

基于多元高熵合金思想制备的高熵合金氮化物薄膜由于多种元素相互混合,易于产生高熵效应、晶格畸变效应和缓慢扩散效应,使得该新型薄膜体系形成简单的非晶结构和纳米晶结构。依赖于成分和制备工艺,多元高熵合金氮化物薄膜表现出简单的固溶体结构和优异的性能,因而在许多领域极具应用潜力。综述了高熵合金氮化物薄膜的发展概况、组织特点、性能特征、制备方法和应用前景,并对高熵合金氮化物薄膜的发展方向进行了展望。     

Topological derivative-based technique for imaging thin inhomogeneities with few incident directions

Many non-iterative imaging algorithms require a large number of incident directions. Topological derivative-based imaging techniques can alleviate this problem, but lacks a theoretical background and a definite means of selecting the optimal incident directions. In this paper, we rigorously analyse the mathematical structure of a topological derivative imaging function, confirm why a small number of incident directions is sufficient, and explore the optimal configuration of these directions. To this end, we represent the topological derivative-based imaging function as an infinite series of Bessel functions of integer order of the first kind. Our analysis is supported by the results of numerical simulations.     

Production of perovskite-like La1−xCaxMnO3+δ ferromagnetic thin films by electrochemical reduction

Ferromagnetic and perovskite-like thin films (<1m) of La1–xCaxMnO3+ have been routinely prepared by heat treatment of an amorphous La–Ca–Mn precursor. The precursor was electrodeposited cathodically in the absence of oxygen and water onto polished silver substrates from a nonaqueous solution of the components' nitrates. Analysis by X-ray diffraction and SQUID magnetometry shows these materials exhibit the appropriate structural and magnetic phases indicative of colossal magnetoresistance.     

Memory effects of all‐solution‐processed oxide thin‐film transistors using ZnO nanoparticles

Abstract— Non‐volatile memory effects of an all‐solution‐processed oxide thin‐film transistor (TFT) with ZnO nanoparticles (NPs) as the charge‐trapping layer are reported. The device was fabricated by using a soluble MgInZnO active channel on a ZrHfO^x gate dielectric. ZnO NPs were used as the charge‐trapping site at the gate‐insulator—channel interface, and Al was used for source and drain electrodes. Transfer characteristics of the device showed a large clockwise hysteresis, which can be used to demonstrate its memory function due to electron trapping in the ZnO NP charge‐trapping layer. This memory effect has the potential to be utilized as a memory application on displays and disposable electronics.     

A new dynamic hydrogen reference electrode for applications in thin-film sensor systems

The realization and applicability of a new dynamic hydrogen reference electrode (DHRE) within an electrochemical microcell for sensor applications is reported. The electrodes are fabricated in thin-film technology and fixed within a flow-through device. An experimental setup for accurate electrochemical potential measurements is described. Smooth platinum, platinized platinum and pHEMA coated electrodes are investigated with regard to their initialization behavior, stability, reproducibility and interference with electrolytes. It is found that platinized platinum DHREs show excellent stability and reproducibility. For uncoated electrodes, the electrochemical potential is established within seconds. The potential is independent of the pH value within the range of pH 4–10. Interference with sulfate and phosphate is observed. Thus, the platinized platinum DHRE is well suited for bioanalytical sensor applications, where the pH value is buffered and the concentrations of the disturbing anions are constant or very low.     

Nanoparticle-based lift-off technique for ultra-thin nanoporous film preparation

Ultra-thin membrane with nanoscale through hole has great potential in biomedical applications, where precise controllability of porosity, pore size and film thickness is urgently required. The present work proposed a cost-effective way to prepare the ultra-thin nanoporous film with a promising controllability. Monodispersed nanoparticle, rather than photoresist, is used as the sacrificial material for this new lift-off process. By releasing the particles, holes can be achieved with predeter-mined characters. A 110 nm-thick nanoporous aluminum film with well-controlled pore＇s diameter was successfully fabricated to validate the technique. The technique has wider process window and better applicability than other nanofabrication methods.     

cdSe_xTe_(1-x)薄膜电极光溶解性能的研究

用循环伏安法对半导体Cdse_xTe_(1-x)薄膜电池的光溶解性能进行了研究。在1mol/L KCl溶液中测量光溶解产物的阴极还原特性,考察了在多硫化钠,多硫化钾及铁氰化钾溶液中的光腐蚀行为。用此方法还研究了薄膜电极表面的光刻蚀过程和pH的影响,并用X射线光电子能谱分析光刻进行不同时间后,电极表面发生的变化。