Reusable Polyacrylonitrile-Sulfur Extractor of Heavy Metal Ions from Wastewater

Mercury, lead, and cadmium are among the most toxic and carcinogenic heavy metal ions (HMIs), posing serious threats to the sustainability of aquatic ecosystems and public health. There is an urgent need to remove these ions from water by a cheap but green process. Traditional methods have insufficient removal efficiency and reusability. Structurally robust, large surface-area adsorbents functionalized with high-selectivity affinity to HMIs are attractive filter materials. Here, an adsorbent prepared by vulcanization of polyacrylonitrile (PAN), a nitrogen-rich polymer, is reported, giving rise to PAN-S nanoparticles with cyclic π-conjugated backbone and electronic conductivity. PAN-S can be coated on ultra-robust melamine (ML) foam by simple dipping and drying. In agreement with hard/soft acid/base theory, N- and S-containing soft Lewis bases have strong binding to Hg²⁺, Pb²⁺, Cu²⁺, and Cd²⁺, with extraordinary capture efficiency and performance stability. Furthermore, the used filters, when collected and electrochemically biased in a recycling bath, can release the HMIs into the bath and electrodeposit on the counter-electrode as metallic Hg⁰, Pb⁰, Cu⁰, and Cd⁰, and the PAN-S@ML filter can then be reused at least 6 times as new. The electronically conductive PAN-S@ML filter can be fabricated cheaply and holds promise for scale-up applications.     

Enhanced properties for visible-light-driven photocatalysis of Ag nanoparticle modified Bi2MoO6 nanoplates

The visible light driven Bi₂MoO₆ photocatalyst doped with different contents of Ag nanoparticles was successfully synthesized by a combination of hydrothermal and sonochemical methods. The as-synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopy (SEM and TEM) and UV–visible spectroscopy to investigate crystalline structure, morphology, composition and photocatalytic properties. XRD patterns and TEM images of the samples revealed pure phase orthorhombic Bi₂MoO₆ nanoplates without any detection of Ag dopant due to its low concentration and very tiny particle size. TEM images showed that Ag nanoparticles with the size of 10–15 nm were dispersed randomly on the surface of Bi₂MoO₆. The XPS analysis of Ag/Bi₂MoO₆ nanocomposites revealed the presence of additional metallic Ag. Photocatalytic activities of the Ag/Bi₂MoO₆ nanocomposites were evaluated by determining the degradation of rhodamine B (RhB) under visible light radiation. In this research, the 10 wt% Ag/Bi₂MoO₆ nanocomposites showed the best photocatalytic activity. The results suggest that the dispersion of Ag nanoparticles on the surface of Bi₂MoO₆ significantly enhances its photocatalytic activity.     

Effect of H2O2 concentration on electrochemical growth and properties of vertically oriented ZnO nanorods electrodeposited from chloride solutions

In this work, ZnO nanostructures are electrodeposited on a transparent conducting glass from chloride baths. The influence of H₂O₂ concentration on the electrochemical characteristics has been studied using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. From the analysis of the current transients on the basis of the Scharifker–Hills model, it is found that nucleation mechanism is progressive with a typical three-dimensional (3D) nucleation and growth process; independently with the concentration of H₂O₂. However, the nucleation rate of the ZnO changes with the increase of H₂O₂ concentration. The Mott–Schottky measurements demonstrate an n-type semiconductor character for all samples with a carrier density varying between 5.14×10¹⁸ cm⁻³ and 1.47×10¹⁸ cm⁻³. Scanning electron microscopy (SEM) observations show arrays of vertically aligned ZnO nanorods (NRs) with good homogeneity. The X-ray diffraction (XRD) patterns show that the ZnO deposited crystallises according to a hexagonal Würtzite-type structure and with the c-axis perpendicular to the electrode surface. The directional growth along (002) crystallographic plane is very important for deposits obtained at 5 and 7 mM of H₂O₂. The high optical properties of the ZnO NRs with a low density of deep defects was checked by UV–vis transmittance analyses, the band gap energy of films varies between 3.23 and 3.31 eV with transparency around 80–90%.     

Post-combustion of mazut with CO2 capture using aspen hysys

There is a wide range of resources for CO₂ emissions. The net amount of CO₂ emissions in the cement industry due to the consumption of fossil fuels and the chemical processes of cement production under heating raw materials is reported to be in the range of 15–25%; this industry, among all the industries and after the power plants and refineries, is the largest CO₂ gas producer throughout the world. Using CO₂ capture and storage (CCS), it can reduce greenhouse gas emissions in a short time. In this study, the technical feasibility study of recycling CO₂ in Abyek Cement Company, with a cement production capacity of about 12,500 tons per day in two production lines, has been studied as one of the largest cement industries throughout the world. Fuel oil (Mazut) is used as the primary fuel for furnaces in this industry. Affected by combustion, the emissions emitted from the five-stage preheater contain 5/24% vol% of CO₂, 7.6% H₂O, 4.8% vol% of O₂, and 63.1% N₂.     

3-甲氧基-5-氯-2,6-二硝基吡啶的合成

以3,5-二氯吡啶为原料,通过甲氧化、硝化合成了重要中间体3-甲氧基-5-氯-2,6-二硝基吡啶,熔点115~117℃,总收率46%,并通过IR、1HNMR、MS和元素分析对产品进行了表征。     

小尺寸LLM-105的重结晶控制方法研究

采用溶剂-非溶剂重结晶法研究了影响LLM-105晶体形貌和粒度大小的因素及影响觃律,选取浓硫酸为溶剂、水为反溶剂,采用反加法研究了溶剂反溶剂体积比、结晶温度、搅拌速度等主要因素对结晶形貌和粒度的影响。结果表明,在搅拌速度500r·min-1、溶剂非溶剂体积比2:15、结晶温度65℃的条件下,重结晶得到的LLM-105晶体形貌觃则,棱角圆滑,长径比在1~1.5之间,粒度均匀,粒度分布在1~10μm之间,平均粒径D50为4.48μm;放热峰温352.9℃,较原料提高了7.2℃,热安定性更好;机械感度降低,撞击感度和摩擦感度分别下降了80%和59%。     

Going from green to white color electroluminescence through a nanoscale complex of Zinc (II)

In this paper, we report application of four novel Nano Zinc (II) complexes as the emitter dyes in organic light emitting diodes (OLEDs). The Nano Zinc (II) complexes emission, particularly its absorption, fluorescence spectra and quantum yield, tuned by varying sizes which affects environments of the Zinc (II) ion. OLED Devices with Nano Zinc (II) complexes were fabricated, giving rise to devices with peak emission ranging from 498 to 541 nm. Here, we have successfully employed sonoelectrochemical method for fabricating white OLEDs. The white emission ascribed to the exciton emission in Nano Zinc (II) complex emitter and from exciplex formation at the interface of PVK/Nano Zinc (II) complex. The experimental results demonstrate that this approach is ideal for color tuning of single and multilayer conducting semiconducting thin films used in the fabrication of organic electronic devices such as OLEDs.     

Efficient red phosphorescent organic light emitting diodes based on solution processed all-inorganic cesium lead halide perovskite as hole transporting layer

An efficient red phosphorescent organic light emitting diode (PhOLED) has been realized by utilizing a composite hole transporting layer comprised of all-inorganic cesium lead halide perovskite CsPbBr₃ via spin-coating and 1,3-bis(9-carbazolyl) benzene (mCP) by vacuum depositing, in which CsPbBr₃ film is used as a hole transporting layer and mCP plays a dominant role in electron and exciton blocking. And this PhOLED shows a saturated red emission coordinated at CIE (0.65, 0.33) driven at 7.5 V, a maximum brightness of 20,750 cd/m², and a maximum current efficiency of 10.64 cd/A, which is as 1.87 times as that 5.68 cd/A of the reference PhOLEDs based on traditional small organic molecular hole transporting material N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzi (NPB). The electroluminescent (EL) spectra and the energy level alignment of different PhOLEDs are investigated. The enhanced EL performances are ascribed to improved hole injecting and transporting behaviors, and better electron and exciton confinements by introducing the composite hole transporting layer CsPbBr₃/mCP.