Direct Z-scheme Cu2O/WO3/TiO2 nanocomposite as a potential supercapacitor electrode and an effective visible-light-driven photocatalyst.

This paper presents the synthesis of visible light-responsive ternary nanocomposites composed of cuprous oxide (Cu2O), tungsten trioxide (WO3), and titanium dioxide (TiO2) with varying weight percentages (wt.%) of the Cu2O. The resulting Cu2O/WO3/TiO2 (CWT) nanocomposites exhibited band gap energy ranging from 2.35 to 2.90 eV. Electrochemical and photoelectrochemical (PEC) studies confirmed a reduced recombination rate of photoexcited charge carriers in the CWT nanocomposites, facilitated by a direct Z-scheme heterojunction. The 0.50CWT nanocomposite demonstrated superior photodegradation activity (2.29 × 10-2 min-1) against Reactive Black 5 (RB5) dye under visible light activation. Furthermore, the 0.50CWT nanocomposite exhibited excellent stability with 80.51% RB5 photodegradation retention after five cycles. The 0.50CWT electrode achieved a maximum specific capacitance of 66.32 F/g at 10 mA/g current density, with a capacitance retention of 95.17% after 1000 charge-discharge cycles, affirming its stable and efficient supercapacitor performance. This was supported by well-defined peaks in cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) curves, indicating pseudocapacitive properties.

Incorporation of Ag in Co9S8-Ni3S2 for Predominantly Enhanced Electrocatalytic Activities for Oxygen Evolution Reaction: A Combined Experimental and DFT Study.

Electrodeposition of abundant metals to fabricate efficient and durable electrodes play a viable role in advancing renewable electrochemical energy technologies. Herein, we deposit Co9S8-Ag-Ni3S2@NF onto nickel foam (NF) to form Co9S8-Ag-Ni3S2@NF as a highly efficient electrode for oxygen evolution reaction (OER). The electrochemical investigation verifies that the Co9S8-Ag-Ni3S2@NF electrode exhibits superior electrocatalytic activity toward OER because of its nanoflowers' open-pore morphology, reduced overpotential (η10 = 125 mV), smaller charge transfer resistance, long-term stability, and a synergistic effect between various components, which allows the reactants to be more easily absorbed and subsequently converted into gaseous products during the water electrolysis process. DFT calculation also reveals that the introduction of Ag (222) surface into the Co9S8 (440)-Ni3S2 (120) system increases the electronic density of states per unit cell of a system and significantly reduces the energy barriers of intermediates for OER, leading to enhanced electrocatalytic activity for OER. This study showcases the innovation of employing trimetallic nanomaterials immobilized on a conductive, continuous porous three-dimensional network formed on a nickel foam (NF) substrate as a highly efficient catalyst for OER.

Highly Selective Electroreduction of Nitrobenzene to Aniline by Co-Doped 1T-MoS2.

The selective electrocatalytic reduction of nitrobenzene (NB) to aniline demands a desirable cathodic catalyst to overcome the challenges of the competing hydrogen evolution reaction (HER), a higher overpotential, and a lower selectivity. Here, we deposit Co-doped 1T MoS2 on Ti mesh by the solvothermal method with different doping percentages of Co as x % Co-MoS2 (where x = 3, 5, 8, 10, and 12%). Because of the lowest overpotential, lower charge-transfer resistance, strong suppression of the competing HER, and higher electrochemical surface area, 8% Co-MoS2 achieves 94% selectivity of aniline with 54% faradaic efficiency. The reduction process follows first-order dynamics with a reaction coefficient of 0.5 h-1. Besides, 8% Co-MoS2 is highly stable and retains 81% selectivity even after 8 cycles. Mechanistic studies showed that the selective and exothermic adsorption of the nitro group at x % Co-MoS2 leads to a higher rate of NB reduction and higher selectivity of aniline. The aniline product is successfully removed from the solution by polymerization at FTO. This study signifies the impact of doping metal atoms in tuning the electronic arrangement of 1T-MoS2 for the facilitation of organic transformations.

Phase-Selective Synthesis of Cobalt Sulfide Heterostructure Catalysts as Efficient Counter Electrodes in Dye-Sensitized Solar Cells.

Developing a cost-saving, high-efficiency, and simple synthesis of counter electrode (CE) material to replace pricy Pt for dye-sensitized solar cells (DSSCs) has become a research hotspot. Owing to the electronic coupling effects between various components, semiconductor heterostructures can significantly enhance the catalytic performance and endurance of counter electrodes. However, the strategy to controllably synthesize the same element in several phase heterostructures used as the CE in DSSCs is still absent. Here, we fabricate well-defined CoS2 /CoS heterostructures and use them as CE catalysts in DSSCs. The as-designed CoS2 /CoS heterostructures display high catalytic performance and endurance for the triiodide reduction in DSSCs thanks to the combined and synergistic effects. As a result, a DSSC with CoS2 /CoS achieves a high energy conversion with an efficiency of 9.47 % under standard simulated solar radiation, surpassing that of pristine Pt-based CE (9.20 %). Besides, the CoS2 /CoS heterostructures possess a quick activity initiation process and extended stability, broadening their potential applications in various areas. Therefore, our proposed synthetic approach could offer new insights for synthesizing functional heterostructure materials with improved catalytic activities in DSSCs.

Sn Anodes Protected by Intermetallic FeSn2 Layers for Long-lifespan Sodium-ion Batteries with High Initial Coulombic Efficiency of 93.8.

With a theoretical capacity of 847 mAh g-1 , Sn has emerged as promising anode material for sodium-ion batteries (SIBs). However, enormous volume expansion and agglomeration of nano Sn lead to low Coulombic efficiency and poor cycling stability. Herein, an intermetallic FeSn2 layer is designed via thermal reduction of polymer-Fe2 O3 coated hollow SnO2 spheres to construct a yolk-shell structured Sn/FeSn2 @C. The FeSn2 layer can relieve internal stress, avoid the agglomeration of Sn to accelerate the Na+ transport, and enable fast electronic conduction, which endows quick electrochemical dynamics and long-term stability. As a result, the Sn/FeSn2 @C anode exhibits high initial Coulombic efficiency (ICE=93.8 %) and a high reversible capacity of 409 mAh g-1 at 1 A g-1 after 1500 cycles, corresponding to an 80 % capacity retention. In addition, NVP//Sn/FeSn2 @C sodium-ion full cell shows outstanding cycle stability (capacity retaining rate of 89.7 % after 200 cycles at 1 C).

Asymmetric Activation of the Nitro Group over a Ag/Graphene Heterointerface to Boost Highly Selective Electrocatalytic Reduction of Nitrobenzene.

The electrocatalytic reduction of nitrobenzene to aniline normally faces high overpotential and poor selectivity because of its six-electron redox nature. Herein, a Ag nanoparticles/laser-induced-graphene (LIG) heterointerface was fabricated on polyimide films and employed as an electrode material for an efficient nitrobenzene reduction reaction (NBRR) via a one-step laser direct writing technology. The first-principles calculations reveal that Ag/LIG shows the lowest activation barriers for the NBRR, which could be attributed to the optimum adsorption of the H atom realized by the appropriate interaction between Ag/LIG heterointerfaces and nitrobenzene. As a result, the overpotential of the NBRR is reduced by 217 mV after silver loading, and Ag/LIG shows a high aniline selectivity of 93%. Furthermore, an electrochemical reduction of nitrobenzene in tandem with an electrochemical oxidative polymerization of aniline was designed to serve as an alternative method to remove nitrobenzene from the aqueous solution. This strategy highlights the significance of heterointerfaces for efficient electrocatalysts, which may stimulate the development of novel electrocatalysts to boost the electrocatalytic activity.

Unilateral pulmonary oedema: a case report and literature review.

Acute myocarditis is often secondary to an acute virus infection, which can be the first manifestation of upper respiratory tract symptoms, followed by chest tightness, shortness of breath, palpitations, chest pain and other non-specific symptoms. In severe cases, it can quickly progress to serious complications such as heart failure, shock and respiratory failure. Laboratory examinations can show an increase of myocardial injury markers, infection and inflammatory indicators. Cardiac ultrasound can detect the weakening of the myocardial contraction and valve regurgitation. On imaging, bilateral pulmonary oedema demonstrates symmetrical infiltration along the hilum of lung, called the "butterfly shadow". This current case report describes a patient with unilateral pulmonary oedema caused by myocarditis that was initially misdiagnosed and treated as pneumonia. The patient was subsequently treated with the application of extracorporeal membrane oxygenation and he made a full recovery. A review of this case highlights that when a patient's symptoms are not typical, a comprehensive examination and evaluation are required to avoid incorrect treatment.

Low cost, robust, environmentally friendly, wood supported 3D-hierarchical Cu3SnS4 for efficient solar powered steam generation.

Solar steam generation has great potential in alleviating freshwater crises, particularly in regions with accessible seawater and abundant insolation. Inexpensive, efficient, and eco-friendly photothermal materials are desired to fabricate sunlight-driven evaporation devices. Here, we have designed an economical strategy to fabricate a high-performance wood-based solar steam generation device. In current study, 3D-hierarchical Cu3SnS4 has been loaded on wood substrates of variable sizes via an in-situ solvothermal method. Considering the water transportation capacity and thermal insulation property of wood, an enhanced light absorption was achieved by a uniform coating of Cu3SnS4 on the inside and outside of the 3D porous structure of the wood. Thanks for the synergistic effect of Cu3SnS4 and wood substrate, the obtained composite endorsed high-performance solar steam generation with a steam generation efficiency of 90% and an evaporation rate as high as 1.35 kg m-2h-1 under one sun.

Selective Electrosynthesis of 2,5-Diformylfuran in a Continuous-Flow System.

The gram-scale selective oxidation of biomass-based chemicals, in particular 5-hydroxymethylfurfural (HMF), into value-added 2,5-diformylfuran (DFF) has a high application potential but suffers from high cost, low selectivity, and harsh reaction conditions. Besides, the electrooxidation strategy requires the usage of expensive electrodes and struggles with low selectivity and efficiency, which restricts its further scaled-up application. In this regard, a continuous-flow system was developed through redox mediator I- /I2 for the efficient synthesis of DFF, which could accelerate the mass transfer of I- (I2 ) to aqueous (organic) phase and avoid over-oxidation to achieve high selectivity. After the solvent system, iodine concentration, and reaction time were optimized, highly efficient DFF synthesis (selectivity >99 %) could be achieved in the electrochemical flow system using inexpensive graphite felt (GF) as electrode. Moreover, selective HMF oxidation was paired with the hydrogen evolution reaction with increased efficiency after using in-situ-loaded GF-CoS2 /CoS and GF-Pt electrodes. As a result, the required energy to achieve the gram-scale synthesis of DFF was significantly reduced, demonstrating outstanding potential for large-scale production of the target product.

Donor-π-Acceptor Heterosystem-Functionalized Porous Hollow Carbon Microsphere for High-Performance Li-S Cathode Materials with S up to 93 wt.

Lithium-sulfur (Li-S) batteries, as a prospective energy storage system, are still plagued by many problems that prevent them from their application, especially the low content of sulfur in the cathode. Herein, a cathode material with S up to 93 wt % is designed via a hollow donor-π-acceptor heterosystem, which combines catalytic sites, adsorption sites, and good conductivity together. Following this guidance, a hollow porous carbon sphere is prepared with CoO particles and single V atoms decorated on it (Co/V-HPCS), providing ultrahigh volumetric space for sulfur. Even the electrode made of sulfur-loaded Co/V-HPCS (Co/V-HPCS@S) has a high content of 90 wt % (sulfur content in the electrode is ∼83.5 wt %), and the cathode exhibits an excellent discharge capacity of 575.2 mAh g-1 under 0.2C after 100 cycles. With careful analysis by means of a high-resolution transmission electron microscope (HRTEM), the catalytic amounts of CoO particles and single V atoms loaded on the carbon shell are confirmed, which endows the material with outstanding catalytic ability to transfer sulfur and excellent adsorption of polysulfides. This concept of the cathode material increases the possibility of advanced long-life Li-S batteries with high tap density and high energy density.

Morphology genetic 3D hierarchical SnO2microstructures constructed by Sub 5 nm nanocrystals for highly sensitive ethanol-sensor.

SnO2is widely used for ethanol-sensing applications due to its excellent physicochemical properties, low toxicity and high sensitivity. However it is a challenge to construct 3D-hierarchical structures with sub 5 nm primary grain particle, which is the optimized size for ethanol sensor. Herein, genetic tri-level hierarchical SnO2microstructures are synthesised by the genetic conversion of 3D hierarchical SnS2flowers assembled by ultrathin nanosheets. The SnS2nanosheets are morphology genetic converted to porous nanosheets with sub 5 nm SnO2nanoparticles during the calcination process. When used for the detection of ethanol, the sensor exhibits a high sensitivity of 0.5 ppm (Ra/Rg = 6.8) and excellent gas-sensing response (Ra/Rg= 183 to 100 ppm) with short response/recovery time (12 s/11 s). The excellent gas sensing performance is much better than that of the previous reported SnO2-based sensors. The highly sensitivity is attributed to the large surface area derived from the recrystallization and volume changes, which offers more active sites during the morphology genetic conversion from SnS2to SnO2. Furthermore, the flower-like 3D structure enhances the stability of the materials and is beneficial for the mass diffusion dynamics of ethanol.

A Microporous Hydrogen-Bonded Organic Framework for the Efficient Capture and Purification of Propylene.

Adsorptive separation of propylene/propane (C3 H6 /C3 H8 ) mixture is desired for its potential energy saving on replacing currently deployed and energy-intensive cryogenic distillation. Realizing efficient C3 H6 /C3 H8 separation in the emerging hydrogen-bonded organic frameworks (HOFs) is very challenging owing to the lack of functional sites for preferential gas binding. By virtue of crystal engineering, we herein report a functionalized HOF (HOF-16) with free -COOH sites for the efficient separation of C3 H6 /C3 H8 mixtures. Under ambient conditions, HOF-16 shows a significant C3 H6 /C3 H8 uptake difference (by 76 %) and selectivity (5.4) in contrast to other carboxylic acid-based HOFs. Modeling studies indicate that free -COOH groups together with the suitable pore confinement facilitate the recognition and high-density packing of gas molecules. The separation performance of HOF-16 was validated by breakthrough experiments. HOF-16 is stable towards strong acidity and water.

Chemical Coupled PEDOT:PSS/Si Electrode: Suppressed Electrolyte Consumption Enables Long-Term Stability.

Huge volume changes of Si during lithiation/delithiation lead to regeneration of solid-electrolyte interphase (SEI) and consume electrolyte. In this article, γ-glycidoxypropyl trimethoxysilane (GOPS) was incorporated in Si/PEDOT:PSS electrodes to construct a flexible and conductive artificial SEI, effectively suppressing the consumption of electrolyte. The optimized electrode can maintain 1000 mAh g-1 for nearly 800 cycles under limited electrolyte compared with 40 cycles of the electrodes without GOPS. Also, the optimized electrode exhibits excellent rate capability. The use of GOPS greatly improves the interface compatibility between Si and PEDOT:PSS. XPS Ar+ etching depth analysis proved that the addition of GOPS is conducive to forming a more stable SEI. A full battery assembled with NCM 523 cathode delivers a high energy density of 520 Wh kg-1, offering good stability.

Self-Supported NaTi2(PO4)3 Nanorod Arrays: Balancing Na+ and Electron Kinetics via Optimized Carbon Coating for High-Power Sodium-Ion Capacitor.

The NaTi2(PO4)3 (NTP) anode materials exhibit high Na+ diffusion dynamics; carbon-based materials can effectively improve its limited electronic conductivity. However, the low Na+ diffusion of NTP/C composite materials from inhomogeneous carbon mixing or uncontrollable carbon coating cannot keep up with fast electron transfer, leading to undesirable electrochemical performances. Herein, a uniform and controllable carbon layer is designed on the self-supported-coated NTP nanorod arrays with binder-free (NTP@C NR) to improve Na+ and electron kinetics simultaneously. As a result, the NTP@C NR electrodes possess initial coulombic efficiency (ICE = 97%), good rate capabilities (89.1 mA h g-1 at 100 C), and stability with ≈78.4% of capacity retention rate at even 30 C over 1200 cycles. The sodium-ion capacitors with NTP@C NR as an anode and commercially activated carbon as a cathode exhibit ∼9180.0 W kg-1 of power density at 10 A g-1 and super high retention of ≈94.5% at 1 A g-1 over 7000 cycles. This work will help balance transport kinetics between the ion and electron for materials applied in storage devices.

Ion-Cross-Linking-Promoted High-Performance Si/PEDOT:PSS Electrodes: The Importance of Cations' Ionic Potential and Softness Parameters.

PEDOT: PSS has been studied as a silicon-based binder due to its inherent superior electricity and electrochemical stability. However, it cannot effectively alleviate the huge volume changes of silicon during lithiation/delithiation due to its linear structure, resulting in poor cycling stability. Ion-cross-linking is a usual method to cross-link linear polymers into 3D structures. In this paper, multivalent cations of the 5th period and Group 2 cross-linked PEDOT:PSS were applied as silicon anode binders and studied systematically. It was found that the variation trend of viscosity and conductivity of PEDOT:PSS after cross-linking was consistent with that of ionic potential and softness parameters of multivalent cations. The mesostructure of a binder after cross-linking is influenced by the solubility product constant of sulfites or hydroxides of cations and the growth characteristics of crystals. An Sn4+-cross-linked binder displayed increased viscosity and electrical conductivity and higher reduced modulus and hardness due to its positive softness parameter and higher ion potential. The Si electrode with the Sn4+-cross-linked binder showed improved cycling stability (1876.4 mAh g-1 compared with 1068.4 mAh g-1 of the electrode with the pure PEDOT:PSS binder after 100 cycles) and superior rate capability (∼800 mAh g-1 at an ultrahigh current density of 8.0 A g-1).

Glycerol-crosslinked PEDOT:PSS as bifunctional binder for Si anodes: Improved interfacial compatibility and conductivity.

Developing conductive polymer binders is a new way to enhance the electric connectivity and mechanical contact of Si based anode material. While the linear structure of commercial PEDOT:PSS cannot effectively alleviate the volume expansion of Si. Herein, glycerol was introduced as a cross-linker to PEDOT:PSS binder for Si anodes, which can further improve the interfacial compatibility between silicon and PEDOT:PSS. After crosslinking, the peel force increased 2 times. As a result, the Si nanoparticles anode with the glycerol-crosslinked binder exhibited a high reversible capacity of 1951.5 mAh g-1 after 200 cycles at 0.5 A g-1 and superior rate capability (804 mAh g-1 at a high current of 8.0 A g-1) for the inherent superior conductivity of PEDOT:PSS.

Mixed Metal-Organic Framework with Multiple Binding Sites for Efficient C2 H2 /CO2 Separation.

The separation of C2 H2 /CO2 is particularly challenging owing to their similarities in physical properties and molecular sizes. Reported here is a mixed metal-organic framework (M'MOF), [Fe(pyz)Ni(CN)4 ] (FeNi-M'MOF, pyz=pyrazine), with multiple functional sites and compact one-dimensional channels of about 4.0 Šfor C2 H2 /CO2 separation. This MOF shows not only a remarkable volumetric C2 H2 uptake of 133 cm3 cm-3 , but also an excellent C2 H2 /CO2 selectivity of 24 under ambient conditions, resulting in the second highest C2 H2 -capture amount of 4.54 mol L-1 , thus outperforming most previous benchmark materials. The separation performance of this material is driven by π-π stacking and multiple intermolecular interactions between C2 H2 molecules and the binding sites of FeNi-M'MOF. This material can be facilely synthesized at room temperature and is water stable, highlighting FeNi-M'MOF as a promising material for C2 H2 /CO2 separation.

Well-defined CoSe2@MoSe2 hollow heterostructured nanocubes with enhanced dissociation kinetics for overall water splitting.

Hollow heterostructures have tremendous advantages in electrochemical energy storage and conversion areas due to their unique structure and composition characteristics. Here, we report the controlled synthesis of hollow CoSe2 nanocubes decorated with ultrathin MoSe2 nanosheets (CoSe2@MoSe2) as an efficient and robust bifunctional electrocatalyst for overall water splitting in a wide pH range. It is found that integrating ultrathin MoS2 nanosheets with hollow CoSe2 nanocubes can provide abundant active sites, promote electron/mass transfer and bubble release and facilitate the migration of charge carriers. Additionally, the surface electron coupling in the heterostructures enables it to serve as a source of sites for H+ and/or OH- adsorption, thus reducing the activation barrier for water molecules adsorption and dissociation. As a result, the title compound, CoSe2@MoSe2 hollow heterostructures, exhibits an overpotential of 183 mV and 309 mV at a current density of 10 mA cm-2 toward hydrogen evolution reactions and oxygen evolution reactions in 1.0 M KOH, respectively. When applied as both cathode and anode for overall water splitting, a low battery voltage of 1.524 V is achieved along with excellent stability for at least 12 h. This work provides a new idea for the design and synthesis of high-performance catalysts for electrochemical energy storage and conversion.

Highly active nanostructured CoS2/CoS heterojunction electrocatalysts for aqueous polysulfide/iodide redox flow batteries.

Aqueous polysulfide/iodide redox flow batteries are attractive for scalable energy storage due to their high energy density and low cost. However, their energy efficiency and power density are usually limited by poor electrochemical kinetics of the redox reactions of polysulfide/iodide ions on graphite electrodes, which has become the main obstacle for their practical applications. Here, CoS2/CoS heterojunction nanoparticles with uneven charge distribution, which are synthesized in situ on graphite felt by a one-step solvothermal process, can significantly boost electrocatalytic activities of I-/I3- and S2-/Sx2- redox reactions by improving absorptivity of charged ions and promoting charge transfer. The polysulfide/iodide flow battery with the graphene felt-CoS2/CoS heterojunction can deliver a high energy efficiency of 84.5% at a current density of 10 mA cm-2, a power density of 86.2 mW cm-2 and a stable energy efficiency retention of 96% after approximately 1000 h of continuous operation.

Utilizing the Space-Charge Region of the FeNi-LDH/CoP p-n Junction to Promote Performance in Oxygen Evolution Electrocatalysis.

The modulation of electron density is an effective option for efficient alternative electrocatalysts. Here, p-n junctions are constructed in 3D free-standing FeNi-LDH/CoP/carbon cloth (CC) electrode (LDH=layered double hydroxide). The positively charged FeNi-LDH in the space-charge region can significantly boost oxygen evolution reaction. Therefore, the j at 1.485 V (vs. RHE) of FeNi-LDH/CoP/CC achieves ca. 10-fold and ca. 100-fold increases compared to those of FeNi-LDH/CC and CoP/CC, respectively. Density functional theory calculation reveals OH- has a stronger trend to adsorb on the surface of FeNi-LDH side in the p-n junction compared to individual FeNi-LDH further verifying the synergistic effect in the p-n junction. Additionally, it represents excellent activity toward water splitting. The utilization of heterojunctions would open up an entirely new possibility to purposefully regulate the electronic structure of active sites and promote their catalytic activities.