rGO@TiO2-x Schottky heterojunction for enhanced bidirectional catalysis in polysulfide conversion.

The shuttling and sluggish conversion kinetics of lithium polysulfides (LiPSs) lead to poor cycling performance and low energy efficiency in lithium-sulfur batteries (LSBs). In this work, a hierarchically structured nanocomposite, synthesized through a surfactant-directed hydrothermal growth following dopamine-protected pyrolysis, serves as a bidirectional catalyst for LSBs. This nanocomposite comprises N-doped reduced graphene oxide (rGO) nanosheets anchored with uniformly distributed TiO2-x nanoparticles via interfacial N-Ti and C-Ti bonding, resulting in the formation of abundant 2D/0D Schottky heterojunctions (rGO/TiO2-x). Density functional theory (DFT) calculations and in situ Raman characterizations demonstrate that rGO/TiO2-x effectively inhibits the shuttling of LiPSs with enhanced redox kinetics, achieving high utilization of the sulfur cathode and improving the overall reversibility. A high areal capacity is attained at a high sulfur loading and a low electrolyte/sulfur ratio. The initial specific capacity reaches 1010 mA h g-1 at a current density of 0.2C (1C = 1675 mA g-1), and a retention of 86.4 % is attained over 100 cycles. A light-emitting diode (LED) screen using two LSBs with rGO/TiO2-x demonstrates their high potential for practical applications.

Sizeable square CsPb2Br5 nanosheets for photodetection.

All-inorganic perovskites have garnered significant attention in optoelectronics. Herein, square CsPb2Br5 nanosheets, with lateral dimensions of up to 200 µm and a thickness of less than 50 nm, were successfully synthesized via a straightforward aqueous method using HBr as a morphology-tailoring agent. A photodetector composed of a single nanosheet was subsequently fabricated and exhibited remarkable photodetection capabilities, demonstrating a detectivity of 5.98 × 109 Jones. These findings offer new perspectives on the synthesis and utilization of CsPb2Br5 and other perovskite nanostructures in optoelectronic devices.

Effect of moxibustion for "nourishing the kidney and benefiting the marrow" on knee osteoarthritis. / "补肾益髓"æ³•è‰¾ç¸æ²»ç–—è†å ³èŠ‚éª¨å ³èŠ‚ç‚Žçš„ç–—æ•ˆè§‚å¯Ÿ.

OBJECTIVES: To compare the clinical effect between two acupoint regimens of moxibustion on knee osteoarthritis (KOA), and observe the influences on the serum content of interleukin 1α (IL-1α), interleukin-17A (IL-17A), tumor necrosis factor α (TNF-α), bone gla protein (BGP) and osteoprotegerin (OPG). METHODS: KOA patients were randomly divided into an observation group (40 cases, 2 cases dropped off) and a control group (40 cases, 3 cases dropped off). In the observation group, moxibustion was applied to Xiyan (EX-LE5), Dubi (ST35), Zusanli (ST36), Dazhu (BL11), Xuanzhong (GB39) and Yongquan (KI1) on the affected side. In the control group, EX-LE5, ST35 and ST36 were selected on the affected side. One session of treatment took 30 min in each group, delivered 3 times a week and the duration of treatment was 4 weeks. The scores of Western Ontario and McMaster University (WOMAC) and visual analogue scale (VAS) were observed and the serum content of IL-1α, IL-17A, TNF-α, BGP and OPG of the two groups were measured before and after treatment. RESULTS: Compared with those before treatment, the WOMAC score, VAS score and the serum content of IL-1α, IL-17A and TNF-α were decreased (P<0.05), and the content of BGP and OPG were increased (P<0.05) after treatment. Compared with the control group, the WOMAC score, VAS score and the serum content of IL-1α and TNF-α in the observation group were lower (P<0.05), and the content of BGP and OPG were higher (P<0.05). The total effective rate of the observation group was 89.5% (34/38), and that of the control group was 83.8% (31/37), with no statistically significant difference. CONCLUSIONS: Moxibustion therapy of "nourishing the kidney and benefiting the marrow" can relieve joint pain, improve joint function, reduce the level of inflammatory factors and ameliorate bone metabolic indicators. The effect of the acupoint regimen in this moxibustion therapy is better than that of the local acupoint selection.

Engineering electronic structures and optical properties of a MoSi2N4 monolayer via modulating surface hydrogen chemisorption.

Recently, a MoSi2N4 monolayer has been successfully synthesized by a delicately designed chemical vapor deposition (CVD) method. It exhibits promising (opto)electronic properties due to a relatively narrow bandgap (∼1.94 eV), high electron/hole mobility, and excellent thermal/chemical stability. Currently, much effort is being devoted to further improving its properties through engineering defects or constructing nanocomposites (e.g., van der Waals heterostructures). Herein, we report a theoretical investigation on hydrogenation as an alternative surface functionalization approach to effectively manipulate its electronic structures and optical properties. The calculation results suggested that chemisorption of H atoms on the top of N atoms on MoSi2N4 was energetically most favored. Upon H chemisorption, the band gap values gradually decreased from 1.89 eV (for intrinsic MoSi2N4) to 0 eV (for MoSi2N4-16H) and 0.25 eV (for MoSi2N4-32H), respectively. The results of optical properties studies revealed that a noticeable enhancement in light absorption intensity could be realized in the visible light range after the surface hydrogenation process. Specifically, full-hydrogenated MoSi2N4 (MoSi2N4-32H) manifested a higher absorption coefficient than that of semi-hydrogenated MoSi2N4 (MoSi2N4-16H) in the visible light range. This work can provide theoretical guidance for rational engineering of optical and optoelectronic properties of MoSi2N4 monolayer materials via surface hydrogenation towards emerging applications in electronics, optoelectronics, photocatalysis, etc.

Nitrogen-doped hollow carbon@tin disulfide as a bipolar dynamic host for lithium-sulfur batteries with enhanced kinetics and cyclability.

Lithium-sulfur batteries (LSBs) are promising next-generation electrochemical energy storage systems owing to high theoretical specific capacity (1675 mAh/g) and low cost. However, the shuttling effect of soluble polysulfides with slow conversion kinetics has deferred their commercial applications. The feasible design and synthesis of composite cathode hosts offer a promise solution to improving their electrochemical performances. In this work, tin disulfide (SnS2) nanosheets were anchored on nitrogen-doped hollow carbon with mesoporous shells, forming a bipolar dynamic host ("SnS2@NHCS"). It can efficiently confine the polysulfides and promote their conversion during (dis)charge. The as-assembled LSBs delivered a high capacity, superior rate and cyclability. This work presents a new view on the exploration of novel composite electrode materials for various rechargeable batteries with emerging applications.

Fabrication of Zn-Cu-Ni Ternary Oxides in Nanoarrays for Photo-Enhanced Pseudocapacitive Charge Storage.

To meet the increasing demands of energy consumption, sustainable energy sources such as solar energy should be better employed to promote electrochemical energy storage. Herein, we fabricated a bifunctional photoelectrode composed of copper foam (CF)-supported zinc-nickel-copper ternary oxides in nanoarrays (CF@ZnCuNiOx NAs) to promote photo-enhanced pseudocapacitive charge storage. The as-fabricated CF@ZnCuNiOx NAs have shown both photosensitive and pseudocapacitive characteristics, demonstrating a synergistic effect on efficient solar energy harvest and conversion. As a result, a high areal specific capacitance of 2741 mF cm-2 (namely 418 µAh cm-2) under light illumination can be calculated at 5 mA cm-2, which delivered photo-enhancement of 38.3% compared to that obtained without light. In addition, the photoelectric and photothermal effects of the light energy on pseudocapacitive charge storage have been preliminarily studied and compared. This work may provide some evidence on the different mechanisms of photoelectric/thermal conversion for developing solar-driven energy storage devices.

Synchronous Defect and Interface Engineering of NiMoO4 Nanowire Arrays for High-Performance Supercapacitors.

Developing high-performance electrode materials is in high demand for the development of supercapacitors. Herein, defect and interface engineering has been simultaneously realized in NiMoO4 nanowire arrays (NWAs) using a simple sucrose coating followed by an annealing process. The resultant hierarchical oxygen-deficient NiMoO4@C NWAs (denoted as "NiMoO4-x@C") are grown directly on conductive ferronickel foam substrates. This composite affords direct electrical contact with the substrates and directional electron transport, as well as short ionic diffusion pathways. Furthermore, the coating of the amorphous carbon shell and the introduction of oxygen vacancies effectively enhance the electrical conductivity of NiMoO4. In addition, the coated carbon layer improves the structural stability of the NiMoO4 in the whole charging and discharging process, significantly enhancing the cycling stability of the electrode. Consequently, the NiMoO4-x@C electrode delivers a high areal capacitance of 2.24 F cm-2 (1720 F g-1) at a current density of 1 mA cm-2 and superior cycling stability of 84.5% retention after 6000 cycles at 20 mA cm-2. Furthermore, an asymmetric super-capacitor device (ASC) has been constructed with NiMoO4-x@C as the positive electrode and activated carbon (AC) as the negative electrode. The as-assembled ASC device shows excellent electrochemical performance with a high energy density of 51.6 W h kg-1 at a power density of 203.95 W kg-1. Moreover, the NiMoO4//AC ASC device manifests remarkable cyclability with 84.5% of capacitance retention over 6000 cycles. The results demonstrate that the NiMoO4-x@C composite is a promising material for electrochemical energy storage. This work can give new insights on the design and development of novel functional electrode materials via defect and interface engineering through simple yet effective chemical routes.

High-performance ternary organic photovoltaics with NC70BA as the third component material enabling thickness-insensitive photoactive performance.

In this work, a thinner (100 nm) and thicker (150 and 200 nm) ternary organic photovoltaic (OPV) are fabricate by D18 as donor, Y6 as acceptor and NC70BA as third component materials. The addition of the hollow 3D spherical structure of NC70BA into D18:Y6 binary films is helpful for improving phase separation and smooth surface of ternary photoactive layer, and form more continuous electron transport channels in ternary photoactive layers. It is enhance photovoltaic performance under not only thinner photoactive layer thickness but also thicker photoactive layer thickness. Our results demonstrate the feasibility of employing D18:Y6 as a binary photovoltaic layer and fullerene derivative NC70BA as a third component material and has construct high-efficiency thickness-insensitive ternary OPVs; this approach would promote the development of thicker photoactive layer ternary OPVs to fulfill the requirements of solution coating processes.

A MoS2@SnS heterostructure for sodium-ion storage with enhanced kinetics.

Layered metal sulphides are promising anode materials for sodium-ion batteries (SIBs) and capacitors owing to their distinctive crystal structures and large interlayer spacings, which are suitable for Na+ insertion/extraction. However, low electronic conductivity, sluggish ion transfer and large volume variation of metal sulphides during sodiation/desodiation processes have hindered their practical application. In this work, we report the construction of a walnut-like core-shell MoS2@SnS heterostructure composite as an anode for SIBs with high capacity, remarkable rate and superior cycling stability. Experimental observations and first-principles density functional theory (DFT) calculations reveal that the enhanced electrochemical performances can be mainly ascribed to the boosted charge transfer and ion diffusion capabilities at the heterostructure interface driven by a self-building internal electric field. Our findings herein may pave the way for the development of novel heterostructure composite materials for beyond lithium-ion batteries and capacitors.

Unprecedented and highly stable lithium storage capacity of (001) faceted nanosheet-constructed hierarchically porous TiO2/rGO hybrid architecture for high-performance Li-ion batteries.

Active crystal facets can generate special properties for various applications. Herein, we report a (001) faceted nanosheet-constructed hierarchically porous TiO2/rGO hybrid architecture with unprecedented and highly stable lithium storage performance. Density functional theory calculations show that the (001) faceted TiO2 nanosheets enable enhanced reaction kinetics by reinforcing their contact with the electrolyte and shortening the path length of Li+ diffusion and insertion-extraction. The reduced graphene oxide (rGO) nanosheets in this TiO2/rGO hybrid largely improve charge transport, while the porous hierarchy at different length scales favors continuous electrolyte permeation and accommodates volume change. This hierarchically porous TiO2/rGO hybrid anode material demonstrates an excellent reversible capacity of 250 mAh g-1 at 1 C (1 C = 335 mA g-1) at a voltage window of 1.0-3.0 V. Even after 1000 cycles at 5 C and 500 cycles at 10 C, the anode retains exceptional and stable capacities of 176 and 160 mAh g-1, respectively. Moreover, the formed Li2Ti2O4 nanodots facilitate reversed Li+ insertion-extraction during the cycling process. The above results indicate the best performance of TiO2-based materials as anodes for lithium-ion batteries reported in the literature.

MOF-derived nitrogen-doped core-shell hierarchical porous carbon confining selenium for advanced lithium-selenium batteries.

The lithium-selenium (Li-Se) battery has attracted growing interest recently due to its high energy density and theoretical capacity. However, the shuttle effect and volume change during cycling severely hinder its further application. In this work, we report a metal-organic framework (MOF)-derived nitrogen-doped core-shell hierarchical porous carbon (N-CSHPC) with interconnected meso/micropores to effectively confine Se for high-performance Li-Se batteries. The micropores were located at the ZIF-8-derived core and the ZIF-67-derived shell, while mesopores appeared at the core-shell interface after the pyrolysis of the core-shell ZIF-8@ZIF-67 precursor. Such a special hierarchical porous structure effectively confined selenium and polyselenides to prevent their dissolution from the pores and also alleviated the volume change. In particular, in situ nitrogen doping, which afforded N-CSHPC, not only improved the electrical conductivity of Se but also provided strong chemical adsorption on Li2Se, as confirmed by density functional theory calculations. On the basis of dual-physical confinement and strong chemisorption, Se/N-CSHPC-II (molar ratio of Co source to Zn source of 1.0 in the core-shell ZIF-8@ZIF-67 precursor) exhibited reversible capacities of up to 555 mA h g-1 after 150 cycles at 0.2 C and 462 mA h g-1 after 200 cycles at 0.5 C and even a discharge capacity of 432 mA h g-1 after 200 cycles at 1 C. Our demonstration here suggests that the carefully designed Se/C composite can improve the reversible capacity and cycling stability of Se cathodes for Li-Se batteries.

Boosting Lithium-Ion Storage Capability in CuO Nanosheets via Synergistic Engineering of Defects and Pores.

CuO is a promising anode material for lithium-ion batteries due to its high theoretical capacity, low cost, and non-toxicity. However, its practical application has been plagued by low conductivity and poor cyclability. Herein, we report the facile synthesis of porous defective CuO nanosheets by a simple wet-chemical route paired with controlled annealing. The sample obtained after mild heat treatment (300°C) exhibits an improved crystallinity with low dislocation density and preserved porous structure, manifesting superior Li-ion storage capability with high capacity (~500 mAh/g at 0.2 C), excellent rate (175 mAh/g at 2 C), and cyclability (258 mAh/g after 500 cycles at 0.5 C). The enhanced electrochemical performance can be ascribed to the synergy of porous nanosheet morphology and improved crystallinity: (1) porous morphology endows the material a large contact interface for electrolyte impregnation, enriched active sites for Li-ion uptake/release, more room for accommodation of repeated volume variation during lithiation/de-lithiation. (2) the improved crystallinity with reduced edge dislocations can boost the electrical conduction, reducing polarization during charge/discharge. The proposed strategy based on synergic pore and defect engineering can pave the way for development of advanced metal oxides-based electrodes for (beyond) Li-ion batteries.

Coherent TiO2/BaTiO3 heterostructure as a functional reservoir and promoter for polysulfide intermediates.

A porous TiO2/BaTiO3 heterostructure composite has been developed as a polysulfide mediator for lithium-sulfur batteries. Superior electrochemical performance has been achieved, mainly attributed to the synergy of TiO2 and BaTiO3 with dual affinity to polysulfides from chemical and ferroelectric-induced polarization effects, and enhanced redox kinetics propelled by the TiO2/BaTiO3 heterojunctions.

SnS2/TiO2 nanohybrids chemically bonded on nitrogen-doped graphene for lithium-sulfur batteries: synergy of vacancy defects and heterostructures.

Despite their high-energy density, low cost and environmental friendliness, the commercial application of lithium-sulfur batteries (LSBs) has been plagued by their severe capacity decay during long-term cycling caused by polysulfide shuttling. Herein, we demonstrate a synergetic vacancy and heterostructure engineering strategy using a nitrogen-doped graphene/SnS2/TiO2 (denoted as NG/SnS2/TiO2) nanocomposite to enhance the electrochemical performance of LSBs. It is noted that plentiful sulfur vacancy (Vs) defects and nanosized heterojunctions are created on the NG/SnS2/TiO2 composite as proved using electron paramagnetic resonance, transmission electron microscopy and X-ray photoelectron spectroscopy, which can serve as strong adsorption and activation sites for polar polysulfide intermediates, prevent their dissolution/shuttling, and accelerate their redox reaction. The novel NG/SnS2/TiO2-S cathode delivers a high initial capacity of 1064 mA h g-1 at 0.5 C and a high capacity retention rate of 68% after 500 cycles at 0.5 C.

Elongation Factor Thermo Unstable (EF-Tu) Moonlights as an Adhesin on the Surface of Mycoplasma hyopneumoniae by Binding to Fibronectin.

Mycoplasma hyopneumoniae is a colonizing respiratory pathogen that can cause great economic losses to the pig industry worldwide. Although putative virulence factors have been reported, the pathogenesis of this species remains unclear. Here, we used the virulent M. hyopneumoniae strain 168 to infect swine tracheal epithelial cells (STEC) to identify the infection-associated factors by two-dimensional electrophoresis (2-DE). Whole proteins of M. hyopneumoniae were obtained and compared with samples cultured in broth. Six differentially expressed proteins with an increase in abundance of ≥1.5 in the cell infection group were successfully identified. A String network of virulence-associated proteins showed that all the six differential abundance proteins were involved in virulence of M. hyopneumoniae. One of the most important upregulated hubs in this network, elongation factor thermo unstable (EF-Tu), which showed a relatively higher expression in M. hyopneumoniae-infected STEC and obtained a higher score on mass spectrometry was successfully recombined. In addition to its canonical enzymatic activities in protein synthesis, EF-Tu was also reported to be located on the cell surface as an important adhesin in many other pathogens. The cell surface location of EF-Tu was then observed in M. hyopneumoniae with flow cytometry. Recombinant EF-Tu (rEF-Tu) was found to be able to adhere to STEC and anti-rEF-Tu antibody enclosed M. hyopneumoniae decreased adherence to STEC. In addition, surface plasmon resonance (SPR) analysis showed that rEF-Tu could bind to fibronectin with a specific and moderately strong interaction, a dissociation constant (KD) of 605 nM. Furthermore, the block of fibronectin in STEC also decreased the binding of M. hyopneumoniae to the cell surface. Collectively, these data imply EF-Tu as an important adhesin of M. hyopneumoniae and fibronectin as an indispensable receptor on STEC. The binding between EF-Tu with fibronectin contributes to the adhesion of M. hyopneumoniae to STEC. HIGHLIGHTS Elongation factor thermo unstable (EF-Tu) exists on the cell surface of M. hyopneumoniae.EF-Tu moonlights as an adhesin of M. hyopneumoniae.The adhesive effect of EF-Tu is partly meditated by fibronectin.

Coherent nanoscale cobalt/cobalt oxide heterostructures embedded in porous carbon for the oxygen reduction reaction.

Cost-effective and efficient electrocatalysts for the oxygen reduction reaction (ORR) are crucial for fuel cells and metal-air batteries. Herein, we report the facile synthesis of a Co/CoO/Co3O4 heterostructure embedded in a porous carbon matrix by refluxing and annealing. This composite exhibits several structural merits for catalyzing the ORR: (1) the existence of metallic Co and graphitic carbon enhanced the electrical conduction; (2) the porous, loose carbon network facilitated the electrolyte permeation and mass transport; (3) more importantly, the nanosized coherent CoO/Co3O4 heterojunctions with structural defects and oxygen vacancies enhanced the charge transport/separation at the interface and adsorption affinity to O2, thus promoting the ORR kinetics and lowering the reaction barrier. Consequently, the composite electrode manifests high electrocatalytic activity, attaining a current density of 6.7 mA cm-2 at -0.8 V (vs. Ag/AgCl), which is superior to pure CoO nanoparticles (4.7 mA cm-2), and has good methanol tolerance. The present strategy based on heterostructure and vacancy engineering may pave the way for the exploration of more advanced, low-cost electrocatalysts for electrochemical reduction and evolution processes.

Superior Pseudocapacitive Lithium-Ion Storage in Porous Vanadium Oxides@C Heterostructure Composite.

Vanadium oxides are promising anode materials for lithium-ion batteries (LIBs) due to their high capacity, good safety, and low cost. However, their practical application has been deferred by the poor rate capability and cycling stability. In this work, we report the designed synthesis of porous V2O3/VO2@carbon heterostructure electrode for high-performance LIBs. The synergic effects of porous nanostructures, phase hybridization with self-building electric field at heterointerface, and conductive carbon implantation effectively enhance the electronic/ionic conduction and buffer the volume variation in the composite material. Electrochemical tests reveal that the composite electrode exhibits high Li-ion storage capacities of 503 and 453 mAh/g at 100 and 500 mA/g, as well as good cycling stability with a retained capacity of 569 mAh/g over 105 cycles at 100 mA/g. In-depth kinetics analysis discloses that pseudocapacitive Li-ion storage process dominates in the composite electrode, which is probably enabled by efficient coupling of the heterostructure components. The strategy of in situ carbon implantation and phase hybridization presented herein may be extended to other electrode materials for rechargeable batteries with superior electrochemical properties.

Amorphous/crystalline hybrid MoO2 nanosheets for high-energy lithium-ion capacitors.

A carbon-free MoO2 nanosheet with amorphous/crystalline hybrid domain was synthesized, and demonstrated to be an efficient host material for lithium-ion capacitors. Discrepant crystallinity in MoO2 shows unique boundaries, which can improve Li-ion diffusion through the electrode. Improved rate capacities and cycling stability open the door to design of high-performance lithium ion capacitor bridging batteries and supercapacitors.

Walnut-like Porous Core/Shell TiO2 with Hybridized Phases Enabling Fast and Stable Lithium Storage.

TiO2 is a promising and safe anode material for lithium ion batteries (LIBs). However, its practical application has been plagued by its poor rate capability and cycling properties. Herein, we successfully demonstrate a novel structured TiO2 anode with excellent rate capability and ultralong cycle life. The TiO2 material reported here shows a walnut-like porous core/shell structure with hybridized anatase/amorphous phases. The effective synergy of the unique walnut-like porous core/shell structure, the phase hybridization with nanoscale coherent heterointerfaces, and the presence of minor carbon species endows the TiO2 material with superior lithium storage properties in terms of high capacity (∼177 mA h g-1 at 1 C, 1 C = 170 mA g-1), good rate capability (62 mA h g-1 at 100 C), and excellent cycling stability (∼83 mA h g-1 was retained over 10 000 cycles at 10 C with a capacity decay of 0.002% per cycle).

High Efficiency CdS/CdSe Quantum Dot Sensitized Solar Cells with Two ZnSe Layers.

CdS/CdSe quantum dot sensitized solar cells (QDSCs) have been intensively investigated; however, most of the reported power conversion efficiency (PCE) is still lower than 7% due to serious charge recombination and a low loading amount of QDs. Therefore, suppressing charge recombination and enhancing light absorption are required to improve the performance of QDSCs. The present study demonstrated successful design and fabrication of QDSCs with a high efficiency of 7.24% based on CdS/CdSe QDs with two ZnSe layers inserted at the interfaces between QDs and TiO2 and electrolyte. The effects of two ZnSe layers on the performance of the QDSCs were systematically investigated. The results indicated that the inner ZnSe buffer layer located between QDs and TiO2 serves as a seed layer to enhance the subsequent deposition of CdS/CdSe QDs, which leads to higher loading amount and covering ratio of QDs on the TiO2 photoanode. The outer ZnSe layer located between QDs and electrolyte behaves as an effective passivation layer, which not only reduces the surface charge recombination, but also enhances the light harvesting.