Hierarchical (Ni,Co)0.85Se sheets for efficient oxygen evolution reaction electrocatalysis: a combined approach of fabrication control and mechanistic understanding.

We present a fabrication process for hierarchical (Ni,Co)0.85Se sheets, achieving efficient oxygen evolution reaction (OER) activity with a 10 mA cm-2 current density at an overpotential of 290 mV. Porous architecture and doping improve kinetics, supported by DFT calculations. This approach offers insights into designing stable, high-performance OER catalysts.

Ultrathin Mo2S3 Nanowire Network for High-Sensitivity Breathable Piezoresistive Electronic Skins.

Flexible piezosensing electronic skins (e-skins) have attracted considerable interest owing to their applications in real-time human-health monitoring, human-machine interactions, and soft bionic robot perception. However, the fabrication of piezosensing e-skins with high sensitivity, biological affinity, and good permeability at the same time is challenging. Herein, we designed and synthesized Mo2S3 nanowires by inserting ∞1[Mo2+S] chains between MoS2 interlayers. The resulting Mo2S3 nanowires feature high conductivity (4.9 × 104 S m-1) and a high aspect ratio (∼200). An ultrathin (∼500 nm) Mo2S3 nanowire network was fabricated using a simple liquid/liquid interface self-assembly method, showing high piezoresistive sensitivity (5.65 kPa-1), a considerably low pressure detection limit (0.08 Pa), and gratifying air permeability. Moreover, this nanowire network can be directly attached to human skin for real-time human pulse detection, finger movement monitoring, and sign language recognition, exhibiting excellent potential for health monitoring and human-machine interactions.

Modulating Cation Migration and Deposition with Xylitol Additive and Oriented Reconstruction of Hydrogen Bonds for Stable Zinc Anodes.

Highly reversible plating/stripping in aqueous electrolytes is one of the critical processes determining the performance of Zn-ion batteries, but it is severely impeded by the parasitic side reaction and dendrite growth. Herein, a novel electrolyte engineering strategy is first proposed based on the usage of 100 mM xylitol additive, which inhibits hydrogen evolution reaction and accelerates cations migration by expelling active H2 O molecules and weakening electrostatic interaction through oriented reconstruction of hydrogen bonds. Concomitantly, xylitol molecules are preferentially adsorbed by Zn surface, which provides a shielding buffer layer to retard the sedimentation and suppress the planar diffusion of Zn2+ ions. Zn2+ transference number and cycling lifespan of Zn∥Zn cells have been significantly elevated, overwhelmingly larger than bare ZnSO4 . The cell coupled with a NaV3 O8 cathode still behaves much better than the additive-free device in terms of capacity retention.

Renewable P-type zeolite for superior absorption of heavy metals: Isotherms, kinetics, and mechanism.

Zeolite is a characteristic material for removing heavy metals exhibiting by low tolerance quantities. It is particularly desirable although challenging to cultivate an unmodified and reusable zeolite for eradicating heavy metals with great capacity. Herein, we sought out and firstly synthesized the uniform octahedral zeolite Na6Al6Si10O32·12H2O for heavy metal ions trap, proven extraordinarily effective decontamination of M2+ (Pb2+, Cd2+, Cu2+, and Zn2+). The maximum capacities of Pb2+, Cd2+, Cu2+, and Zn2+ were 649, 210, 90 and 88 mg/g, and the distribution coefficients (Kd) was ~108 mL/g for Pb2+ which emphasized the superior effectiveness of Na6Al6Si10O32·12H2O contrasted with other zeolites. Rapid adsorption was observed that Pb2+ concentration (7.5 ppm) was reduced to 0.6 ppb in 2 min. The removal mechanism was ascribed to the ion exchange and hydroxyl groups thereby affording high adsorption capacity. We also investigated the heavy metal removal of zeolite 13X and 4A for comparison and concluded the determining factor affecting absorption capacity. The removal rate of Pb remained at 97% even after five regeneration recycles. The zeolite was therefore promising for practical water purification and industrialization.

ZnO-Templated Selenized and Phosphorized Cobalt-Nickel Oxide Microcubes as Rapid Alkaline Water Oxidation Electrocatalysts.

Oxygen electrocatalysis is of remarkable significance for electrochemical energy storage and conversion technologies, together with fuel cells, metal-air batteries, and water splitting devices. Substituting noble metal-based electrocatalysts by decidedly effective and low-cost metal-based oxygen electrocatalysts is imperative for the commercial application of these technologies. Herein, a novel strategy is presented to fabricate selenized and phosphorized porous cobalt-nickel oxide microcubes by using a sacrificial ZnO spherical template and the resulting microcubes are employed as an oxygen evolution reaction (OER) electrocatalyst. The selenized samples manifest desirable and robust OER performance, with comparable overpotential at 10 mA cm-2 (312 mV) as RuO2 (308 mV) and better activity when the current reaches 13.7 mA cm-2 . The phosphorized samples exhibit core-shell structure with low-crystalline oxides inside amorphous phosphides, which ensures superior activity than RuO2 with the same overpotential (at 10 mA cm-2 ) yet lower Tafel slope. Such a surface doping method possibly will provide inspiration for engineering electrocatalysts applied in water oxidation.

"Electron-Sharing" Mechanism Promotes Co@Co3O4/CNTs Composite as the High-Capacity Anode Material of Lithium-Ion Battery.

Hybridization of nanostructured cobalt oxides with carbon nanotubes (CNTs) is considered to be an operative approach to harvest high-performance anode material for lithium-ion batteries (LIBs). On the other hand, there are numerous related works, most of which adopted a "post-combination" strategy, which is not only complicated but also ecologically unpromising for using toxic acid for surface modification of CNTs. Herein, we productively fabricate Co@Co3O4/CNTs nanocomposite with excellent conductivity through arc discharge following low-temperature oxidation in air. As the anode material for LIBs, this nanocomposite shows an exceedingly high reversible capacity of 820 mA h g-1 at a current density of 0.2 A g-1 after 250 cycles, much higher than its theoretical capacity. The rate performance of the material is also outstanding, with a capacity of 760 mA h g-1 after 350 cycles at 1 A g-1 (103% of the initial capacity) and 529 mA h g-1 after 600 cycles at 2 A g-1. X-ray photoelectron spectroscopy tests are accomplished to disclose the true cause of extra capacity. And for the first time, we propose an "electron-sharing" storage mode, where extra electrons and Li+ can separate and be stored at the interface of cobalt metal/Li2O. This not only gives a reasonable revelation for this unusual capacity exceeding the theoretical value but also directs the capacitor-like electrochemical behavior extra capacity.

Charge-Transfer-Promoted High Oxygen Evolution Activity of Co@Co9S8 Core-Shell Nanochains.

Co@Co9S8 nanochains with core-shell structures are prepared by a direct-current arc-discharge technique and followed sulfurization at 200 °C. The nanochains, which consist of uniform nanospheres connecting each other, can range up to several micrometers. The thickness of Co9S8 shell can be changed by regulating the sulfurization time. In this heterostructure of Co@Co9S8, Co nanochains function as a conductive network and can inject electrons into Co9S8, which manipulates the work function of Co9S8 and makes it more apposite for catalysis. The density functional theory calculation also reveals that coupling with Co can significantly reduce the overpotential needed to drive the oxygen evolution process. On the basis of the exclusive structure, Co@Co9S8 nanochains have shown high catalytic activity in the oxygen evolution reaction. Co@Co9S8 reaches an overpotential of 285 mv at 10 mA cm-2, which is much lower than that of Co nanochains (408 mV) and Co9S8 (418 mV). Co@Co9S8 also shows higher catalytic activity and robustness compared to state-of-the-art noble-metal catalyst RuO2.

Oxygen Evolution Activity of Co-Ni Nanochain Alloys: Promotion by Electron Injection.

Metal alloy nanoparticles have shown promising applications in electrocatalysis. However, the nanoparticles usually suffer from limited charge-transfer efficiency, which can be solved by preparing one-dimensional materials. Herein, Co-Ni alloy nanochains are prepared by a direct-current arc-discharge method. The nanochains, comprised of mutually coupled uniform nanospheres, can range up to several micrometers in size. When the alloy is exposed to air or under the electro-oxidation process, a metal-metal-oxide heterostructure is obtained. The alloy can inject electrons into the oxide, which makes it more suitable for electrocatalysis. The composition of the samples can be changed by varying the ratio of Ni/Co (i.e., Co, Co7 Ni3 , Co5 Ni5 , Co3 Ni7 , Ni) in the synthesis process. The nanochains show good oxygen evolution performance that correlates with the Ni/Co ratio. Co7 Ni3 demonstrates optimal activity with an onset point of 1.50 V vs. reversible hydrogen electrode (RHE) and overpotential of 350 mV at 10 mA cm-2 . The alloy nanochains also show excellent durability with 95.0 % current retention after a long-term test for 12 h.

Crimean-Congo hemorrhagic fever: Risk factors and control measures for the infection abatement.

Crimean-Congo hemorrhagic fever (CCHF) is a vector-borne viral disease, widely distributed in different regions of the world. The fever is caused by the CCHF virus (CCHFV), which belongs to the Nairovirus genus and Bunyaviridae family. The virus is clustered in seven genotypes, which are Africa-1, Africa-2, Africa-3, Europe-1, Europe-2, Asia-1 and Asia-2. The virus is highly pathogenic in nature, easily transmissible and has a high case fatality rate of 10-40%. The reservoir and vector of CCHFV are the ticks of the Hyalomma genus. Therefore, the circulation of this virus depends upon the distribution of the ticks. The virus can be transmitted from tick to animal, animal to human and human to human. The major symptoms include headache, high fever, abdominal pain, myalgia, hypotension and flushed face. As the disease progresses, severe symptoms start appearing, which include petechiae, ecchymosis, epistaxis, bleeding gums and emesis. Enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, antigen detection, serum neutralization and isolation of the virus by cell culture are the diagnostic techniques used for this viral infection. There is no specific antiviral therapy available thus far. However, ribavirin has been approved by the World Health Organization for the treatment of CCHFV infection. Awareness campaigns regarding the risk factors and control measures can aid in reducing the spread of this disease to a greater extent, particularly in developing countries.