Rechargeable magnesium batteries (RMBs) are appealing alternatives for energy storage systems based on the high theoretical capacity, low price and high security of the Mg metal anode. Nevertheless, the shortage of high-performance cathode materials severely obstructs its development. As an important conversion material, transition metal selenides, with desirable theoretical capacity and weak bond energy (Mg-Se), have attracted more attention in recent years. In this study, CuFeSe2 (CFS) nanoparticles were produced by a hydrothermal approach and its feasibility as a cathode material for RMBs was further investigated. Given the synergistic effect between Cu and Fe, the optimized CFS shows a reversible capacity of 120 mAh g(-1) at 100 mA g(-1), outstanding long-term cyclability (86 mAh g(-1) at 1 A g(-1) after 600 cycles), and prominent rate capability (85 mAh g(-1) at 1 A g(-1)). Density functional theory (DFT) computations conclude CFS exhibits a suitable migration barrier for Mg2+ along the tunnel of 0.92 eV. An in-depth investigation of the mechanism demonstrates that the Mg storage process can be divided into solid solution reaction and the conversion processes by ex-situ techniques. This work contributes to further investigate the Mg2+ storage mechanism of cathode materials for RMBs.

Enhanced polarization emerges as a potent strategy for further enhancing the photocatalytic performance of a photocatalyst. Considering the anisotropy of ferroelectric polarization and the improvement of polarization by defects, [010] preferred growth Bi4Ti3O12 nanowires with oxygen vacancies were prepared via a hydrothermal method. Bi4Ti3O12 nanowires exhibited a photocatalytic NO removal efficiency of up to 67.5% under visible light irradiation (λ > 420nm), which is much higher than that of its counterpart, Bi4Ti3O12 (3%). Structural characterizations and theoretical calculations support that, the engineering of oxygen vacancies in Bi4Ti3O12 can enhance the polarization in the [010] and [100] directions, and gradually shifted the polarization dominant direction of Bi4Ti3O12 from [100] to [010]. Overall, the improved polarization and generated oxygen vacancies enhanced the photocatalytic NO removal performance of Bi4Ti3O12 nanowires. This work elucidates the significance of rational engineering oxygen vacancy-based microstructures and utilizing the polarization to amplify the photocatalytic performance.

Emerging as a leading contender for economical, high-security grid-scale energy storage, rechargeable aqueous zinc-ion batteries (AZIBs) are currently facing the challenge in its progression due to the absence of cathode materials with high energy density. In this study, we design a V2O5 & sdot; nH(2)O, GO and CNTs composite (HVO/GO-CNTs) film through freeze-drying and vacuum filtration. This binder-free cathode for AZIBs exhibits remarkable electrochemical performance, featuring a high capacity of 387 mAh g(-1) at 0.2 A g(-1) and a high capacity retention of 82.6 % after 1000 cycles at 1 A g(-1). This investigation offers a promising approach to electrode material design for the advancement of high-performance AZIBs.

Calciumion batteries (CIBs) are an appealing energy storage technology owing to the low redox potential of Ca2+/Ca and the abundant Ca reserves in the earth's crust. However, suitable cathode materials with high capacity and long lifespan are scarce. Herein, VO2(B)/reduced graphene oxide (rGO) heterojunction formed by interfacial V & horbar;O & horbar;C bonds is constructed and first reported as a cathode material for CIBs, which exhibits an ultrahigh discharge capacity of 319.2 mAh g(-1) and exceptional long lifespan (3000 cycles at 500 mA g(-1) with capacity retention of 85%). In addition, VO2(B)/rGO heterojunction also shows an outstanding rate capability at 50 degrees C (127.1 mAh g(-1) at 1000 mA g(-1)). The remarkable electrochemical performance is attributed to the big tunnel structures of VO2(B) and the role of rGO in enhancing electronic conductivity. Density functional theory calculations reveal a feasible Ca2+ diffusion path at the interface. Furthermore, a reversible single-phase insertion/extraction reaction is revealed by in situ X-ray diffraction, ex situ Raman, and ex situ X-ray photoelectron spectroscopy. This work demonstrates that VO2(B)/rGO holds great potential for building high-capacity and long-lifespan CIBs.

As the prevalence of electromagnetic interference (EMI) continues to rise, there is a growing demand for shielding materials, which play a crucial role in electronic devices, communication systems, and health protection etc. However, conventional EMI shielding materials encounter difficulties in effectively addressing the escalating intricacies of electromagnetic environments and diverse shielding scenarios, wherein foldability, flexibility and lightweight are desired. In this work, we develop a novel EMI shielding material, silver-hollow-fiber (AgHF), by combining blow-spinning, UV radiation and temperature-controlled annealing technologies. During fabrication process, UV radiation was used to selectively reduce silver ions on the outer surface of precursor fiber, and temperature-controlled annealing was further employed to remove the inside polymer, forming a hollow fiber structure. The AgHF exhibits superior flexibility, lightweight, remarkable mechanical stability, and excellent EMI shielding efficiency (SE). Particular, the AgHF with a thickness of 163 μm demonstrates an EMI SE of 101.65 dB, and with minimal degradation of less than 10% even after undergoing 2,000 bending cycles. The remarkable EMI shielding performance, combined with the lightweight, flexibility, and mechanical stability of AgHF, positions it as a highly promising material for a wide range of EMI shielding applications in the future.

Owing to the abundance of calcium and low redox potential and high safety, calcium-ion batteries (CIBs) are considered a promising candidate for post lithium-ion batteries. Cu3(OH)2V2O7·2H2O@rGO with bimetallic redox activity is proposed as a novel cathode material for CIBs.

An Ag decorated magnetic core-shell Fe3O4@MoS2 composite was synthesized in this work to improve the photocatalytic performance and solid-liquid separation of MoS2 based materials. The composite was evaluated by UV-vis IS-NIR spectrometer, photoluminescence (PL) spectra, XRD, XPS, EDS, EIS and was devoted to reduce the toxicity of wastewater which contains hexavalent chromium(Cr(VI)) for its potential economic value. The results have shown that the core-shell structure effectively inhibits the stack of nanosheets, increases the specific surface area of the material, and exposes more active sites. Besides, loading Ag can effectively promote the migration of photogenerated electrons and improve the photocatalytic performance. On this basis, the better separability and retrievability which got form the magnetic core-shell Fe3O4 may immensely promote the photodegradation technique of hexavalent chromium (Cr (VI)) and provided a new strategy for photocatalytic degradation of industrial industrial wastewater that containing hexavalent chromium (Cr (VI)).

In this work, Mn (II) was doped into MoS2 structure and then anchored on activated alumina beads to construct 3D-sized composites (Mn-MoS2@AABs). This component material was used as PMS activator for tetracycline (TC) degradation under light irradiation. According to experiment results, Mn-MoS2@AABs exhibited well degradation performance to TC, which ascribed to excellent photo-response property of Mn-MoS2 and activation of Mn. Importantly, the 3D-sized structure made it facilely be recycled from solution, which catered to the demand for the practical application. Therefore, the novel strategy of designing Mn-MoS2@AABs had great significance for environmental restoration.

alpha-Hydroxy ketones are important building blocks in biological, pharmaceutical and synthetic chemistry. In this work, diverse alpha-hydroxy ketones were efficiently constructed through the CO2-promoted hydration process of propargyl alcohols, which was catalyzed by a system consisted of economical CuSO4 center dot 5H(2)O and a green 1-butyl-3-methylimidazolium acetate ionic liquid. Particularly, this catalytic system exhibited excellent activity under atmospheric CO2 or even mimetic flue gas (20 vol% of CO2). Moreover, this system employed the lowest metal loading ever reported (0.004-0.25 mol%) meanwhile reached the highest turnover number (11700) for the target hydration reaction. Additionally, this is the first reported Cu catalytic system with reliable recyclability, which could be easily reused at least 6 times with yields higher than 85%. (C) 2021 Elsevier Inc. All rights reserved.

Hg-0 has gradually become a serious environmental problem that need to be solved, due to its strong volatility and insolubility in water. In this study, the adsorption behavior of X(O, Se, Te)-doped monolayer MoS2 for was studied via DFT calculation to evaluate its potential for Hg-0 removal. Oxygen group atoms X(O, Se, Te) doped MoS2 systems all have extremely high bonding energies, in which the strong interaction between the dopant atoms and the S vacancy of monolayer MoS2, resulting that dopant systems were greatly stable. Compared with pristine monolayer MoS2, X(O, Se, Te)-doped MoS2 has stronger adsorption performance and electrical conductivity in adsorbing Hg-0, which is mainly attributed to the facilitation of electrons transfer between Hg-0 and MoS2. The oxygen doping system exhibits best adsorption performance to Hg-0, primarily due to the relatively stronger interaction between the dopant oxygen and Hg-0. The results reveal that the O-doped monolayer MoS2 can effectively improve the adsorption efficiency of Hg-0 increasing the application potential for mercury emissions control in coal-fired power plants.

MoS2 has attracted tremendous attention in reducing AuCl4-, however, it suffers from poor stability in solutions. In this work, MoS2 nanosheet wrapped with polydopamine (MoS2@PDA composite) was successfully prepared by simple hydro-thermal synthesis. Compared to pure MoS2, the as-synthesized MoS2@PDA composite exhibited not only excellent stability, but also superb AuCl4- reduction capacity. With the warp of PDA, the thermal stability of the composite was improved obviously, and dissolution of the composite in aqueous solution hardly occurs. Moreover, the reduction of AuCl4- by MoS2@PDA composite could reach equilibrium in 90 min, and the maximum reduction was about 3800 mg/g, and the reaction was intensely pH-dependent. In addition, gold nanoparticles were widely distributed on the surface of MoS2@PDA composite, which could effectively prevent the agglomeration of gold nanoparticles. This finding might point out the possibility of applying MoS2@PDA composite as stable anti-agglomeration substrate for gold nanoparticles.