Synthesis of 2D material based Bi2O3/MXene nanohybrids and their applications for the removal of industrial effluents

2D material-based Bi₂O₃/MXene nanohybrids were successfully fabricated through an ultrasonication method. MXene (Ti₃C₂Tx) nanosheets were prepared via simple H.F. etching while bismuth oxide nanoflowers were prepared by the co-precipitation method. The structure, morphologies, and optical properties of all the prepared samples were analyzed by various advance techniques such as X-ray diffraction (XRD), UV–Visible spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). To check the photocatalytic efficiency of prepared material was performed for both colored and colorless dyes. A significant increase in photocatalytic properties were observed for methylene blue and benzoic acid. The prepared nanohybrid showed 1.6 folds higher efficiency than bismuth oxide nanopetals. The relatively higher utilization e?ciency of sunlight and the rapid separation rate of photogenerated electron and hole pairs helped to enhance the photocatalytic performance synergistically. Additionally, the antibacterial activity of all samples was also carried out using the disc diffusion method against K. pneumonia and S. aureus. Improved properties could be attributed to an increase in d-spacing of 2D MXene layers by inserting nanopetals which reduced the restacking of MXene layers. Furthermore, multiple functional groups on the surface of MXene will also play an important role in enhancing the properties of its nanohybrids. We expect that the as-synthesized nanohybrid will attract researchers’ attentions for the degradation of industrial pollutants.     

Preparations of Complex Bimetallic Oxides from Bimetallic Assemblies Containing Different Copper（Ⅱ） Precursors and Comparison of Some Related Systems

This is a mini-review-like article including our recent results and methods for （new） metal oxides and （previously reported） composite materials composed of metal complexes and metal oxides for comparison to enhance anisotropic structural changes intentionally. Some complex inorganic oxides are known that they may be promising color materials （absorbing visible light of certain wavelengths region） having potential application for environmentally benign catalysts, for example, photocatalysts. Chiral copper（Ⅱ） complexes having bidentate amine ligands （[CuL2]2＋） can be acted as cationic building blocks of bimetallic metal complexes. We have prepared some chiral bimetallic complexes with various anionic metal complexes such as [PtCl4]2-, [M02O7]2 and Mn12 clusters （typical single-molecule magnets） which characterized by means of solid-state electronic and CD （circular dichroism） spectra, IR （infrared） spectra, synchrotron XRD （X-ray diffraction） and XAS （soft X-ray absorption spectroscopy）. By sintering these precursor chiral bimetallic complexes, we have prepared complex inorganic oxides from them. The IR spectra indicated substituting metal-ligand bonds and losing organic moieties. The XRD pattern indicated complete changes of crystal structures. The XAS revealed replacing coordination atoms as well as oxidation of valences of metal ions. Furthermore, we will also investigate possibility of patterning by homogeneous precipitation method as bimetallic complexes to prepare desirable complex inorganic oxides.     

Influence of the iron content in Cu–Ni based inert anodes on their corrosion resistance for aluminium electrolysis

Mechanically alloyed (Cu_3.25Ni)_100−xFe_x materials (x = 0, 15 and 30 wt.%) were evaluated as inert anodes for aluminium electrolysis in KF–AlF₃ (700 °C) electrolyte. For x = 0, the cell voltage was unstable and high (5–6 V) due to the formation of an insulting NiF_x layer at the metal–oxide interface. For x = 15 and 30, the formation of a Cu₂O-rich external scale with a protective NiFe₂O₄-rich intermediate layer was favoured, resulting in a lower (∼4 V) and more stable cell voltage. The purity of the produced Al was 98.96, 99.31 and 99.20 wt.% for x = 0, 15 and 30, respectively.     

交变电磁场与磁致振动对铸铁腐蚀的影响

 为了探究缠绕式电脉冲水处理技术应用过程中，电磁场与磁致振动协同作用对铸铁腐蚀过程的影响。选择铸铁为研究对象，研究了腐蚀过程中溶解氧质量浓度、pH值、铁释放、铸铁挂片表面形态、腐蚀后生成铁系氧化物的结晶形态及组分以及挂片腐蚀速率等参数的特性及变化规律。研究结果表明，交变电磁场与磁致振动协同作用能够有效加速并促进腐蚀反应的阳极反应和阴极反应，使水中溶解氧质量浓度及pH降低，促进铁离子在水中的释放，显著改变腐蚀产物的物相组成及晶体形态。     

Effects of alkaline metal on coal gasification at pyrolysis and gasification phases

A Chinese high-rank coal was acid-washed and ion-exchanged with Na and K to prepare the H-form, Na-form and K-form coals. After pyrolysis, H-form, Na-form and K-form chars and two additional H-form chars (acid washed Na-form and K-form chars) were prepared to investigate the effects of alkaline metal (AM) on coal gasification at the pyrolysis and gasification phases. The H-form char had the highest pryolysis rate; the H-form char had a relative low gasification rate. The AM loaded coals exhibited relative low pyrolysis rate, while the corresponding chars had high gasification reactivity. Acid-washing reduced the reactivities of Na-form and K-form chars. AM inhibited the progress of graphitization of the base carbon resulting in a more reactive char of less ordered crystalline carbon structure. A kinetic model incorporating AM-catalyzed gasification and non-catalytic gasification was developed to describe the gasification rate changes in the char conversion for AM-catalyzed gasification of chars.     

Fabrication of Pb(Zr,Ti)O3 thin films utilizing unconventional powder magnetron sputtering (PMS)

Pb(Zr,Ti)O3 (PZT) ferroelectric ceramic films exhibit highly superior ferroelectric, pyroelectric and piezoelectric properties which are promising for a number of applications including non-volatile random access memory devices, non-linear optics, motion and thermal sensors, tunable microwave systems and in energy harvesting (EH) use. In this research, a thin layer of PZT was deposited on two different substrates of Strontium Titanate (STO) and Strontium ruthenate (SRO) by powder magnetron sputtering (PMS) system. The preliminary powders, consisting of PbO, ZrO₂ and TiO_2, were manually mixed and placed into the target holder of the PMS. The deposition was performed at an elevated temperature reaching up to 600 °C via a ceramic heater. This high temperature is required for PZT thin film crystallinity, which is never achieved in conventional physical vapour deposition processes. The phase structure, crystallite size, stress-strain and surface morphology of deposited thin films were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The composition of the PZT thin films were also analysed by X-ray photoelectron spectroscopy (XPS). The mechanical properties of the thin films were evaluated with micro-scratch adhesive strength and micro hardness equipment. FESEM results showed that the PZT thin films were successfully deposited on both SRO and STO substrates. The surfaces of the coated samples were free from cracks, relatively smooth, uniform and dense. The profile of X-ray diffraction confirmed the formation of single-c-domain/single crystal perovskite phase grown on both substrates. The XPS analysis have shown that the PZT thin film grown by this method and that a target of PZT+10% PbO is a proper target for growing nominal PZT thin films. The adhesion strength and micro hardness results have confirmed the stability and durability of the thin film on the substrates, although higher values have been reported for thin film of PZT deposited on SRO surfaces.     

Fabrication of Ta nanoparticles induced by nanosecond laser ablation in ethanol: the study of laser fluence effects

Tantalum nanoparticles (Ta NPs) were synthesized in ethanol solution by ablation with a 1064 nm Nd:YAG laser. Prepared NPs were investigated by UV-visible absorption spectroscopy, Transmission electron microscopy, X-ray diffraction and Photoluminescence measurement. The average sizes of NPs were calculated to be in the range of 12–18 nm. From the UV-visible studies, the plasmon peak position of Ta NPs was observed in the spectral range of 206–208 nm. The XRD spectra clearly showed the crystalline structure of NPs and various peaks of Ta and Ta₂O₅. Moreover, the UV region in the PL spectrum included the free exciton and the bound exciton emission correlated with the defect concentration. In fact, the laser ablation in the organic and inorganic solvents is a strong technique to obtain some NPs with particular structures, which are impossible to produce by conventional methods.     

用于同步辐射X射线注量绝对测量的自由空气电离室

根据X射线束光子通量、注量和空气比释动能等物理量的关系,通过空气比释动能的测量,转换确定了所需要的光子通量、注量等。依据X射线自由空气电离室原理,针对同步辐射光子束的物理条件,确定了自由空气电离室的设计方案并完成了精密加工和安装调试。电离室主要部件尺寸公差、机械性能和电性能满足计量标准的要求,为计量标准的建立提供了基础。     

High energy (150 MeV) Fe11+ ion beam induced modifications of physico-chemical and photoluminescence properties of high-k dielectric nanocrystalline zirconium oxide thin films

This work presents the influence of dominated electronic energy loss over nuclear energy loss induced by swift heavy ion (SHI) irradiation on the physico-chemical, optical and other properties of RF grown zirconium oxide (ZrO₂) thin films. For this purpose, thin films of ZrO₂ grown on glass substrate were irradiated by 150 MeV Fe¹¹⁺ ions with a range of fluence from 2E12 to 5E13 ions/cm² to understand the mechanism of induced modifications and defects generation. The XRD results confirmed that the virgin and irradiated ZrO₂ thin films were crystalline in nature with monoclinic and tetragonal structure. The crystallite size varied from 19.93 nm to 46.43 nm with varying ion fluence. Strain, dislocation density and stacking fault were used to investigate the changes in structural parameters. Tauc's plot method was employed for the quantitative evaluation of optical energy band gap (E_g) that exist in the range of 4.45–4.62 eV. The transmittance (%) of the virgin and Fe¹¹⁺ ions irradiated samples was determined in the range of 35.69–66.09% using UV–Vis. spectroscopy. Further, the refractive index was determined using different methods significantly depends on the optical band gap. The broad PL emission peaks were obtained at 375 nm and 440 nm with the excitation wavelength (λ_ex.) of 300 nm. The variation in PL intensity with increasing ion fluence was attributed to the creation or annihilation of primary or complex defects. FTIR spectroscopy was employed for the analysis of chemical modifications in vibrational bonds of samples and the band obtained 660 cm⁻¹was assigned to the asymmetrically coupled Zr–O–Zr stretching which presents the strong vibration in samples. The band intensity increased up to the fluence 5E12 ions/cm² and decreased at a higher fluence of 1E13 ions/cm². Rutherford backscattering spectroscopy technique was used to determine the thickness (165 nm) of the samples.