查看更多>>摘要：Bacterial drug resistance caused by the abuse of antibiotics poses a serious threat to human health. Thus, the development of alternative strategies for the replacing of antibiotics is necessary. Herein, a hierarchical three-dimensional Bi2S3 (BS) nanoflowers were facile fabricated and employed as supporter for the growth of silver nanoparticles (Ag NPs). Combining the excellent antimicrobial activity of Ag NPs, the as-resulted Ag/BS exhibited broad-spectrum antibacterial activity against pathogenic bacteria. Investigation on antibacterial mechanism revealed the treatment of Ag/BS damages the bacterial cell membrane, leading to the loss of intracellular substances. The compromised membrane caused the reduction of membrane bound enzymes activity, resulting in the arrest of metabolic activity. Simultaneously, Ag/BS broke the bacterial antioxidant defense system by raising the intracellular ROS levels, caused the oxidative damage, resulting in the loss of bacterial viability. Moreover, the satisfactory biocompatibility and effective antibacterial performance of Ag/BS were confirmed by performing in vitro cytotoxicity and in vivo antibacterial assay. Accordingly, this work opens up possibility for the construction of Bi2S3 based multifunctional nanomaterials and its application for pathogenic bacteria control. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：One-dimensional rod-shaped Ag2Mo2O7/BiOI composite photocatalysts were prepared via a facile hydro-thermal-calcining method. The structure, morphologies, and elemental nature of the photocatalysts were characterized. Ag2Mo2O7/BiOI was formed through the attachment of BiOI nanosheets on the surface of Ag2Mo2O7 rods, resulting in a 1D/2D heterojunction with larger interface area, more surface-active sites, and faster charge transfer channel. The Ag2Mo2O7/BiOI heterogeneous exhibited excellent and stable photodegradation performances for Rhodamine B (RhB) and Tetracycline (TC) under visible light irradiation. At the optimum composition of 15 wt% BiOI, the Ag2Mo2O7/BiOI heterojunction exhibited a highest de-gradation rate for RhB and TC, which were 70 times and 16 times higher than those of Ag2Mo2O7, re-spectively. The improved photocatalytic performance can be attribute to the efficient separation of photoinduced charges caused by the formation of the n-n heterojunction between Ag2Mo2O7 and BiOI. Additionally, the dominant active species of photocatalytic reaction were determined to be .O-2- and h+ by free radical capture experiments and ESR test. In addition, a toxicity test with E. coli was carried out, which shows that the photodegraded Tetracycline solution is basically harmless to E. coli. Based on the experimental results and hybrid density functional theory calculation, a plausible photocatalytic mechanism of n -n heterojunction was proposed. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Artificially designing and preparing composites with unique structure is one of important ways to effectively improve the electromagnetic wave absorption performance. In this study, binary flower-like WS2 /Co hybrid composites through anchoring WS2 nanoclusters on Co nanosheets have been successfully developed. Attributing to the hierarchical structure of the composites, the effective interfacial polarization verifying from distinct Cole-Cole semicircles could improve the dielectric loss substantially, also it enabled the multiple reflections of the incident waves which benefitted for promoting the energy dissipation. Furthermore, the host of lamellate Co could maintain the magnetic characteristic and supply the magnetic loss dominantly caused by natural and exchange resonance deriving from the high planar anisotropy, the guest of WS2 nanoclusters could induce dipole polarization deriving from vacancies of W and S atoms. As a result, excellent wave absorption performance could be achieved for the composites with the minimum RL (RLmin) of - 46.5 dB at 10.2 GHz under a small thickness of 1.7 mm, accompanied by a wide effective bandwidth (RL < -10 dB) covering from 2.7 to 18 GHz with integrated thicknesses from 1.0 to 5.0 mm. Prospectively, this work provides a new opportunity to fabricate the valuable materials for practical electromagnetic wave absorbing applications. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The practical application of aqueous zinc-iodine (Zn-I-2) battery is mainly hindered by the limited electrical conductivity, sluggish kinetics and severe shuttle effect. In this regard, herein, we designed a biomass derived hierarchically porous carbon (marked as BCHP) as an iodine host material for high-performance ZnI2 battery. The hierarchically porous structure of BCHP is favourable for iodine confinements, electrolyte permeation as well as electron/ion transfers. As a result, the I-BCHP electrode exhibits superior electrochemical performance. A high discharge capacity of 100 mAh g(-1) is still retained for over 150 cycles at a current density of 100 mA g(-1). Our study provides an economical and effective scheme for the significant improvement of Zn-I(2 )battery performance. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The flow behavior and dynamic transformation of near beta TC17 alloy with a bimodal structure were investigated by hot compression with the high strain rate range from 1 s-1 to 20 s-1 and in the temperature range from 840 degrees C to 900 degrees C in this study. The most evident discontinuous yielding and post strain hardening occur at 840 degrees C-20 s(-1 )due to its high alpha p volume fraction before compression and the subsequent strong work hardening effect. High strain rate can slightly promote dynamic transformation when alloy is compressed at 840 degrees C and 870 degrees C due to domination of the high flow stress and temperature raising. However, more dramatic dynamic transformation is obtained for 1 s(-1) at 900 degrees C because the deformation heating at higher temperature/lower strain rate is less evident, and the deformation time thus maters more greatly on the phase transformation. The fine alpha s shows an obvious phase transformation priority than the coarse alpha p under all conditions due to the enhanced alloy element (Al) diffusivity resulting from enlarged alpha/beta interface and higher dislocation (diffusion channel) density around it. The alpha p promotes the dynamic re crystallization of beta phase while this effect becomes weaker when dynamic transformation is progressed greatly, mainly due to the inevitable stored energy consumption and reduced alpha p volume fraction caused by phase transformation. (C) 2022 Elsevier B.V. All rights reserved.
Khan, UsmanNairan, AdeelaIrfan, MuhammadNaz, Shafaq...
8页
查看更多>>摘要：Next-generation spintronic applications, including magnetic nanosensors, energy-efficient data storage devices and magnetic memory devices, have obtained scientific and technological interest. One-dimensional (1D) core/shell nanomaterials are particularly interesting due to their promising anisotropic magnetic properties and exchange bias. Here, we investigate a versatile sol-gel and electrochemical deposition method and achieve Ni/BiFeO3 (Ni/BFO)'s controlled growth with tunable structure geometry. Significantly, BFO nanoshells on the pore walls and Ni nanowires inside the nanoshell are successfully deposited. Experimental and analytical observations show that the prepared Ni/BFO nanostructures have the ability to improve magnetic properties. This work presents a pathway for the controlled growth of hybrid nanostructures and provides a platform to study the tunable magnetic properties, suggesting their promise for practical applications. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Low mechanical performance is the key technical problem for metal-based soft magnetic composites (SMCs) with core-shell structures needed to be urgently resolved for their actual applications due to the limitation of their conventional preparation methods. In this work, dense sintered Al2SiO5 ceramic layers have been in situ formed and entirely coated on the surfaces of high-purity deformed Fe particles via a low temperature solid-phase reaction between initially-coated amorphous nano-Al2O3 and nano-SiO2 to obtain a new ceramic-reinforced Fe/Al2SiO5 SMCs. The fully-densified Fe/Al2SiO5 SMCs exhibit a high transverse rupture strength value of 120 MPa, which exceeds those for most of present metal-based SMCs. These ceramic-coated Fe-based composites also show strong corrosion resistance in water-air and salt-water conditions due to the anti-corrosion Al2SiO5 coating layers completely isolating the deformed Fe particles from the corrosion environments. Good magnetic performance is maintained in these high-strength and corrosion-resistant Fe/Al2SiO5 SMCs due to the suitable thickness of Al2SiO5 coating layers, which promises their broad application prospects for high-power electromagnetic devices in critical environments. Moreover, the fabrication for fully-densified functional metal-ceramic composites by a nanoscale solid-state reaction coating method in this work can provide a new insight for the research and applications of the other new-type metal-based composites. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Fabrication of low-cost, stable and highly efficient catalysts for clean energy and environmental control applications is an urgent task. In this work, we have successfully synthesized a multifunctional two-dimensional rare earth-based LaOCl@hcp-Ni heterostructure via a simple one-pot method. Here, the semiconductor LaOCl nanoparticles were well deposited on the metastable metal hcp-Ni, and the hexagonal close-packed structure of hcp-Ni matched the layered-structure LaOCl to form a highly active LaOCl@hcp-Ni Schottky catalyst. Furthermore, LaOCl@hcp-Ni were tested for Photoelectrochemical (PEC) oxygen evolution reaction (OER) in alkaline media and the photocatalytic (PC) degradation of Rhodamine B (RhB) in aqueous solution. LaOCl@hcp-Ni shows excellent PEC-OER catalytic activity and RhB degradation performance under artificial simulated sunlight. This enhancement of PEC and PC performance is due to the Schottky interface constructed by the coupling of hcp-Ni and LaOCl, which generates an interface electric field to effectively promote the transfer of photogenerated electrons from the semiconductor LaOCl to the metal hcp-Ni through the interface. Thus, energy band gap of LaOCl with oxygen defects is adjusted to the visible light region and their valence state of La is lowered, realizing high-efficiency visible light catalytic activity. Thus, it would be a potential rare earth-based Schottky catalyst, which can be used for the PEC oxygen evolution and the PC degradation of organic pollutants.(c) 2022 Published by Elsevier B.V.
查看更多>>摘要：At present, passivated emitter and rear cell (PERC) solar cells dominate the photovoltaic industry. However, light and elevated temperature-induced degradation (LeTID) is an important issue responsible for the reduction of PERC efficiency, which may lead to up to 16% relative performance losses in multicrystalline silicon solar cells, and this degradation occurs in almost all types of silicon wafers. Even in next-generation silicon solar cells like Tunnelling oxide passivated contact (TOPCon) and Heterojunction with Intrinsic Thinlayer (HJT) solar cells, LeTID can still cause an efficiency loss up to 1% relative. LeTID is a long process in terms of time during the whole cycle of degradation and regeneration, which will seriously affect the conversion efficiency and stability of solar modules, and hence increase the cost of electricity generated by solar cells. Furthermore, after years of research on LeTID, researchers are yet to determine the specific cause of LeTID. In this paper, we refer to specific literature, briefly describe the development history of LeTID, introduce the phenomena of LeTID in crystalline silicon solar cells, and describe its characteristics. In addition, we also analyzed the fundamental causes of LeTID, and found that the cause may be related to metal impurities or hydrogen contained in solar cells. At present, in view of the participation of hydrogen in LeTID and other existing related theories, this paper introduces several methods to inhibit LeTID in crystalline silicon. Finally, the content of this paper is summarized, and the development of solar cells in the future is prospected.
查看更多>>摘要：In the present work, effect of heat treatment on microstructure and corrosion behaviour of a high Mo containing alpha + beta titanium alloy (Ti-6Al-1 V-4Mo-0.1Si) has been investigated. Heat treatment results in the formation of wide variety of microstructure depending on the heating temperature (below or above the beta transus) and cooling conditions. Martensite was observed after oil quenching (OQ), Widmanstatten alpha (alpha(WS)) + beta after air cooling (AC) and lamellar alpha (alpha(L)) + beta after furnace cooling (FC). The corrosion behaviour of the heat-treated specimens were studied in simulated body fluid (SBF) at 37 & nbsp;C using open circuit potential time (OCP), electrochemical impedance spectroscopy (EIS) and potentio-dynamic polarization tests. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical nature of the corroded surfaces. The study revealed that, in general, OQed samples had increased corrosion resistance than the ACed and FCed samples. XPS confirmed the presence of TiO2 and Al2O3 on the corroded sample. The alloy's improved corrosion resistance was attributed to stable inert TiO2 film. Samples heat treated at 950 & nbsp;C were found to have better corrosion resistance in general.(C) 2022 Elsevier B.V. All rights reserved.
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