Facile Solvent Research Articles

Valence electronic engineering of hollow-nanocube-structured CoFeNi-layered double hydroxides for highly efficient oxygen evolution

The sluggish kinetics of oxygen evolution reaction (OER) and the high-cost of catalysts currently limit the large-scale industrialization of hydrogen production through water electrolysis, so developing efficient and inexpensive catalysts is a top priority. Herein, we employed a facile solvent method to synthesize a well-defined hollow nanocube-structured CoFeNi layered double hydroxide (LDH) with an optimized valence electronic structure of metal sites as an efficient electrocatalyst for accelerating the kinetics of OER. The optimal catalyst with the regulated valence electronic structure exhibited a strong synergistic catalytic effect and an excellent activity and stability. It achieved a lower overpotential of 294 mV at 100 mA cm−2, and high durability exceeding 100 h at 1 A cm−2, surpassing the performance of commercial Ir-/Ru-based catalysts. The optimized the coordination environment and valence electronic structure of metal sites can definitely serve as active centers for triggering OER, thereby improving the intrinsic electrocatalytic performance.

A non-destructive strategy to construct ZIF-8 interface layer of carbon fiber/hydroxyapatite-epoxy composites

The interface is the transition region between the fiber and the matrix, whose structure and characteristics determine the overall performance and sustained stability of carbon fiber/hydroxyapatite-epoxy (CHR) composites as bone implant materials. Similarly, carbon fibers, as reinforcement, also play an indispensable role in carrying external loads. Therefore, this work focuses on improving the fibers surface in a gentle and non-destructive way to ensure that the reinforcement of both the fibers and the interface is maximized, resulting in excellent mechanical and biotribological properties. In this work, a novel interface layer was designed by introducing zeolitic imidazolate framework-8 (ZIF-8) into CHR with a facile solvent method. The presence of ZIF-8 induces the formation of flower-cluster hydroxyapatite. The complex layer formed by the combination of the polyhedral shape ZIF-8 and the flower-cluster hydroxyapatite enhances the mechanical interlock and chemical interaction between the carbon fibers and the epoxy matrix. It also promotes the penetration and curing process of the epoxy matrix. The tensile strength of ZIF-8 reinforced CHR (ZIF-8@CHR) are 136.97 MPa, which is 38.43 % higher than that of the pristine CHR. And the wear rate (1.18 × 10−14 m3(N·m)−1) of ZIF-8@CHR is decreased by 81.65 %. ZIF-8@CHR with superior mechanical and biotribological properties provides new insights into the biological application of carbon fiber composites as an implant material for fracture fixation or reconstruction.

A facile solvent activation process manipulates the structure and filtration performance of oxidized poly (arylene sulfide sulfone) TFC membrane

In this study, solvent-resistant polyamide (PA) thin film composite (TFC) nanofiltration (NF) membranes were successfully prepared based on an ultrasolvent-resistant oxidized poly (arylene sulfide sulfone) (O-PASS) substrate. The effects of different substrates on interfacial polymerization (IP) process were systematically studied. The O-PASS-TFC membranes were activated to different degrees by a controlled activation process using the mixture solvent of DMF/H2O with different ratio of DMF, the solubility power can be designed by adjusting DMF volume fraction, as the activation solvent. The membrane followed pure DMF treatment was found to have the excellent performance: the surface morphology of TFC membrane was activated to smooth and high negative charged, yield nanofiltration (NF) performance with a solution permeance of 8.82 LMH bar−1 (~621 % increase) and a pure water permeance (PWP) of 11.59 LMH bar−1 (~607 % increase), Na2SO4 rejection maintained above 98.7 %. On the other hands, the same O-PASS-TFC membrane activated with solvent mixture volume ratio of DMF/H2O = 0.5 exhibited enhanced Na2SO4 rejection of 99 %, with greater solution permeance of 3.01 LMH bar−1 (~212 % increase). The correlations between the different activation treatment-membrane structure-separation properties of O-PASS-TFC membranes with different solvent activation degrees were investigated in detail. In this work, the ultrasolvent-resistant property of O-PASS substrate was combined to regulate its TFC membrane structure, and then further to endow the TFC membrane with multiple excellent filtration performance by fully utilizing the solvent activation effect of DMF. Through this strategy, it supplies a facile and promising route for preparation of high efficiency TFC membrane.

Anionic Metal-Organic Framework Derived Cu Catalyst for Selective CO2 Electroreduction to Hydrocarbons.

Metal-organic frameworks (MOFs)-related Cu materials are promising candidates for promoting electrochemical CO2 reduction to produce valuable chemical feedstocks. However, many MOF materials inevitable undergo reconstruction under reduction conditions; therefore, exploiting the restructuring of MOF materials is of importance for the rational design of high-performance catalyst targeting multi-carbon products (C2). Herein, a facile solvent process is choosed to fabricate HKUST-1 with an anionic framework (a-HKUST-1) and utilize it as a pre-catalyst for alkaline CO2RR. The a-HKUST-1 catalyst can be electrochemically reduced into Cu with significant structural reconstruction under operating reaction conditions. The anionic HKUST-1 derived Cu catalyst (aHD-Cu) delivers a FEC2H4 of 56% and FEC2 of ≈80% at -150mAcm-2 in alkaline electrolyte. The resulting aHD-Cu catalyst has a high electrochemically active surface area and low coordinated sites. In situ Raman spectroscopy indicates that the aHD-Cu surface displays higher coverage of *CO intermediates, which favors the production of hydrocarbons.

Liquid Crystal Elastomer Hollow Fibers as Artificial Muscles with Large and Rapid Actuation Enabled by Thermal‐Pneumatic Enhanced Effect

AbstractLiquid crystal elastomer (LCE) has large and reversible deformation under stimulation, making it an ideal material for artificial muscles. Currently, multi‐stimulus responsive LCE actually responds to each stimulus independently rather than responding to several stimuli simultaneously. Achieving an enhanced effect from concurrent stimuli is still a challenge, which requires a new stimulus‐response mechanism. This work develops a novel and facile solvent evaporation‐assisted template method to prepare LCE hollow fiber (LCEHF) with axial alignment. Taking advantage of the enhanced effect of heat‐induced phase transition and mechanical force‐induced orientation transition of mesogens, the LCEHF under both heat and pressure can produce a large contraction ratio of ≈50%, which is higher than 42% of thermal stimulation or 27% of pneumatic stimulation. It can also enhance the respective response and recovery speed of LCEHF to 300 and 3700 times of pneumatic actuation. Additionally, the enhanced effect lowers the actuation temperature much below the phase transition temperature, imparting LCEHF with high mechanical performance during actuation. Furthermore, the dual thermal‐pneumatic responsive LCEHF can mimic human biceps and cause large and rapid bending of an artificial arm reversibly. This new actuation methodology sheds new light on improving LCE actuation performance and broadens its application scenarios.

Solvent-Reconstructed Interface That Enhances Light Out-Coupling in Quasi-Two-Dimensional Perovskite Light-Emitting Diodes.

Light management is critical to maximizing the external quantum efficiency of perovskite light-emitting diodes (PeLEDs), but strategies for enhancing light out-coupling are typically complex and expensive. Here, using a facile solvent treatment strategy, we create a layer of lithium fluoride (LiF) nanoislands that serve as a template to reconstruct the light-extracting interfaces for PeLEDs. The nanoisland interface rearranges the near-field light distribution in order to maximize the efficiency of internal light extraction. With the proper adjustment of the nanoisland size and distribution, we have achieved an optimal balance between charge injection and light out-coupling, resulting in bright, pure-red quasi-two-dimensional PeLEDs with a 21.8% peak external quantum efficiency.

Mn(II)-Based Metal Halide with Near-Unity Quantum Yield for White LEDs and High-Resolution X-ray Imaging.

Metal halides have drawn great interest as luminescent materials and scintillators due to their outstanding optical properties. Exploring new types of phosphors with easy production processes, excellent photophysical properties, high light yields, and environmentally friendly compositions is crucial and quite challenging. Herein, a novel Mn(II)-based metal halide (4-BTP)2MnBr4 was produced using a facile solvent evaporation method, which exhibited a strong green emission peaking at 524 nm from the d-d transition of tetrahedral-coordinated Mn2+ ion and a near-unity quantum yield. The prepared white light-emitting diode device has a wide color gamut of 100.7% NTSC with CIE chromaticity coordinates of (0.32, 0.32). In addition, (4-BTP)2MnBr4 demonstrates excellent characteristics in X-ray scintillation, including a high light yield of 98 000 photons/MeV, a sensitive detection limit of 37.4 nGy/s, excellent resistance to radiation damage, and successful demonstration of X-ray imaging with high resolution at 21.3 lp/mm, revealing the potential for application in diagnostic X-ray medical imaging and industry radiation detection.

Enhanced Dielectric and Electric Properties of ZnFe2O4‐Poly(Vinylidene Fluoride) Composites by Employing Surface Hydroxylated ZnFe2O4 Nanoparticles

AbstractA facile solvent casting technique has been reported in the fabrication of surface hydroxylated ZnFe2O4 (h‐ZFO) nanoparticles (NPs) filled with poly(vinylidene fluoride) (PVDF) as a matrix. The h‐ZFO filler particles are synthesized from neat ZnFe2O4. The dielectric and electric performance of polymer‐based composites is much related to the interface binding between filler particles and polymer matrix. In this work, the surface alternation technique employed a new path is developed to improve the compatibility between ZFO particles and the PVDF matrix. These PVDF‐ZFO composites were studied by X‐ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The h‐ZFO‐PVDF and ZFO‐PVDF composites are carefully analyzed by dielectric and electric properties by a wide range of frequencies. However, the morphological analysis exhibits uniform dispersion of the h‐ZFO NPs in the PVDF matrix. The h‐ZFO‐PVDF composites have a dielectric constant of about 35 for 1.5 wt.% of filler contents. Moreover, the h‐ZFO‐PVDF composites have lower dielectric loss than PVDF‐ZFO composites. It is suggested that the strong interaction between h‐ZFO filler particles and the PVDF matrix is the main reason for the improvement of dielectric properties. The outcomes of these methods have great potential for making high dielectric constants and relatively suppressed loss PVDF‐ZFO composites for advanced practical applications.

S-Nitroso-N-acetylpenicillamine impregnated latex: A new class of barrier contraception for the prevention of intercourse-associated UTIs.

Urinary tract infections (UTIs) are some of the most common infections seen in humans, affecting over half of the female population. Though easily and quickly treatable, if gone untreated for too long, UTIs can lead to narrowing of the urethra as well as bladder and kidney infections. Due to the disease potential, it is crucial to mitigate the development of UTIs throughout healthcare. Unfortunately, sexual activity and the use of condoms have been identified as common risk factors for the development of sexually acquired UTIs. Therefore, this study outlines a potential alteration to existing condom technology to decrease the risk of developing sexually acquired UTIs using S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor. Herein, varying concentrations of SNAP are integrated into commercialized condoms through a facile solvent swelling method. Physical characterization studies showed that 72%-100% of the ultimate tensile strength was maintained with lower SNAP concentrations, validating the modified condom's mechanical integrity. Additionally, the evaluation of room-temperature storage stability via NO release analysis outlined a lack of special storage conditions needed compared to commercial products. Moreover, these samples exhibited >90% relative cell viability and >96% bacterial killing, proving biocompatibility and antimicrobial properties. SNAP-Latex maintains the desired condom durability while demonstrating excellent potential as an effective new contraceptive technology to mitigate the occurrence of sexually acquired UTIs.

Synthesis and structure-dependent optical properties of two new organic-inorganic hybrid antimony(III) chlorides.

Two organic-inorganic hybrid antimony(III) chlorides, namely (C9H26N3)2Sb4Cl18 (1) and (C9H26N3)SbCl6 (2), were prepared using a facile solvent evaporation method. They have low-dimensional structures constructed from SbCl6 octahedra and triply protonated N,N,N',N'',N''-pentamethyldiethylenetriamine cations. The organic cations exhibit different conformations in the two compounds. Compound 1 crystallizes in the centrosymmetric space group P1̄, while compound 2 crystallizes in the noncentrosymmetric space group Pca21. Notably, compound 2 exhibits a moderate second harmonic generation (SHG) response of about 1.3 times that of KH2PO4 (KDP) under 1064 nm laser irradiation. Meanwhile, this compound displays green-yellow luminescence under 342 nm ultraviolet light irradiation, indicating its potential as a bifunctional optical material. Theoretical calculations based on density functional theory were also performed to gain insights into the correlation between their structures and optical properties.

Fabrication of NiWO4/g-C3N4 S-scheme heterojunction photocatalyst for enhanced H2 evolution

Photocatalytic H2 production is a desired route to obtain green H2 for its cleanness and sustainability properties. It is still essential to explore the highly active photocatalysts in this field. Herein, a facile solvent evaporation strategy to fabricate a NiWO4/g-C3N4 heterojunction photocatalyst was employed. The research demonstrates that NiWO4/g-C3N4 hybrids can achieve an obviously enhanced H2 evolution actively, although they have poor activity individually. The H2-releasing rate of 10 % NiWO4/g-C3N4 can reach 2546 μmol·h−1·g−1 under 300 W artificial light source illumination in 20 vol.% TEOA. Further investigations indicate that NiWO4 and g-C3N4 can form S-scheme heterojunction according to band structure analysis and photoelectrochemical tests, which leads to an effective charge separation for the energy band bending, coulomb force and interfacial electric field between g-C3N4 and NiWO4, making reserved charges with higher redox activity. In addition, NiWO4 can reduce the H2 evolution overpotential, favoring fast surface H2-releasing kinetics.

Shape and Stiffness Switchable Hydroplastic Wood with Programmability and Reproducibility.

Stiffness switchable materials (e.g., supramolecular polymers, metals) that alter their shape and mechanical properties in response to specific stimuli are potentially utilized in the structural engineering field but still limited due to the use of petroleum-based synthetic monomers and large energy consumption. Herein, a sustainable and facile solvent casting strategy is proposed to fabricate the "hydroplastic wood" with shape and stiffness switchable properties via cell wall wetting, cell wall softening and subsequent moisture evaporation. Therein, a wetting agent with low surface tension and low viscosity is utilized for covering the rough surface of solid wood to form a liquid lubricating layer, thereby increasing the interfacial wettability and achieving uniform softening of the cell walls. This interface wetting treatment can easily break through the hydro-plasticization process for thick wood (Balsa wood, Ochroma lagopus Swartz, density: 0.25 g/cm3; Pinewood, Pinus armandii, density: 0.38 g/cm3). Additionally, the capillary force arising from moisture evaporation induces the self-densification of oriented cellulose nanofibrils and achieves moisture-mediated shape design capabilities through periodic saturation-dehydration. This work makes hydroplastic wood a promising candidate for engineering materials because of its combined advantages of strong durability, formability, and load-carrying capacity.

Asphaltene-Derived Graphene Quantum Dots for Controllable Coatings on Glass, Fabrics, and Aerogels.

Graphene quantum dots (GQDs) derived from natural asphaltene byproducts can produce controlled hydrophobic or hydrophilic interfaces on glass, fabrics, and aerogels. A set of facile solvent extraction methods were used to isolate and chemically prepare materials with different surface functionalities from a commercially derived asphaltene precursor. The organic-soluble fraction was used to create hydrophobic and water-repellent surfaces on glass and cotton fabrics. The GQD solutions could also penetrate the pores of a silica aerogel, rendering it hydrophobic. Alternatively, by extracting the more polar fraction of the GQDs and oxidizing their surfaces, we also demonstrate strongly hydrophilic coatings. This work shows that naturally abundant GQD-containing materials can produce interfaces with the desired wettability properties through a straightforward tuning of the solvent extraction procedure. Owing to their natural abundance, low toxicity, and strong fluorescence, asphaltene-derived GQDs could thus be applied, in bulk, toward a wide range of tunable surface coatings. This approach, moreover, uses an important large-scale hydrocarbon waste material, thereby offering a sustainable alternative to the disposal of asphaltene wastes.

Solvent Welding-Based Methods Gently and Effectively Enhance the Conductivity of a Silver Nanowire Network

To enhance the conductivity of a silver nanowire (Ag NW) network, a facile solvent welding method was developed. Soaking a Ag NW network in ethylene glycol (EG) or alcohol for less than 15 min decreased the resistance about 70%. Further combined solvent processing via a plasmonic welding approach decreased the resistance about 85%. This was achieved by simply exposing the EG-soaked Ag NW network to a low-power blue light (60 mW/cm2). Research results suggest that poly(vinylpyrrolidone) (PVP) dissolution by solvent brings nanowires into closer contact, and this reduced gap distance between nanowires enhances the plasmonic welding effect, hence further decreasing resistance. Aside from this dual combination of methods, a triple combination with Joule heating welding induced by applying a current to the Ag NW network decreased the resistance about 96%. Although conductivity was significantly enhanced, our results showed that the melting at Ag NW junctions was relatively negligible, which indicates that the enhancement in conductivity could be attributed to the removal of PVP layers. Moreover, the approaches were quite gentle so any potential damage to Ag NWs or polymer substrates by overheating (e.g., excessive Joule heating) was avoided entirely, making the approaches suitable for application in devices using heat-sensitive materials.

Toward Superior Low-Temperature Performance and Safe Cathode Slurry Fabrication via 3-Methoxy-N,N-dimethylpropionamide as a Low-Toxicity and Facile Solvent

Toward Superior Low-Temperature Performance and Safe Cathode Slurry Fabrication via 3-Methoxy-<i>N,N</i>-dimethylpropionamide as a Low-Toxicity and Facile Solvent

Facile Solvent Regulation for Highly Strong and Tough Physical Eutectogels with Remarkable Strain Sensitivity.

Physical eutectogels have great potential for applications in many fields due to their electrical conductivity, broad temperature stability, and biocompatibility. However, the preparation of high-performance physical eutectogels in a simple, efficient, and cost-effective way remains a challenge. In this study, a facile but efficient solvent regulation strategy was proposed to construct a highly robust poly(vinyl alcohol) (PVA) physical eutectogel. Hydrogen bonds within the polymer-containing deep eutectic solvent system were dynamically regulated by the introduction-removal of water to induce the formation of a uniform and dense polymer cross-linked network, which imparted excellent mechanical properties to the resulting eutectogel. For the eutectogel with 15 wt % PVA, the tensile strength and toughness were 1.67 MPa and 6.81 MJ m-3, respectively, which were at a high level among existing physical eutectogels. This high-performance eutectogel was available as a strain sensor and exhibited high sensitivity. In addition, this eutectogel can be endowed with a directional muscle-like stretching performance through convenient mechanical training. The easy scalability and low cost made our method an effective strategy for developing high-performance physical eutectogels, which would further promote the application of such materials in areas such as wearable electronics and soft robotics.

A facile strategy for highly efficient perovskite crystals fabricated in a high moisture environment via solvent engineering process

BackgroundHybrid organic perovskite solar cells (PSCs) have recently gained recognition for their excellent photovoltaic properties. However, most PSCs were fabricated in a nitrogen-filled glovebox to prevent damage from moisture. Overcoming humidity damage is crucial for PSC fabrication in an ambient atmosphere. Fabricating perovskite solar cells (PSCs) under ambient atmosphere conditions needs the aid of substrate heating or air-knife flow to rapidly evaporate solvents. MethodsHerein, we propose a facile solvent engineering method without extra equipment or processes for fabricating highly efficient PSCs in a high moisture condition by a one-step spin-coating process. Acetone incorporation into the perovskite precursor solution not only prevents the ingress of moisture, but also accelerates the volatilization of solvents during the crystallization process. Significant findingsThe as-prepared PSCs feature low trap-state density, high charge recombination resistance, low hysteresis, and long charge lifetime. Little MABr and PbBr2 are separated out to passivate interface/grain-boundary defects. At a 10% acetone incorporation, the highest power conversion efficiency can reach 17.75% for the PSC fabricated in 70% relative humidity. The work provides a facile, promising method to prepare highly efficient PSCs in an ambient atmosphere.

Fabrication of S-scheme FeCoS2/Red phosphorus heterojunction for efficient photocatalytic H2 evolution

Establishing efficient charge transfer channels remains a great challenge to improve the photocatalytic activity of red phosphorus (RP). Herein, the flower-like spherical FeCoS2 was employed to improve the activity of RP nanosheets, S-scheme FeCoS2/RP heterojunction was obtained through a facile solvent evaporation strategy. The optimized 5 wt% FeCoS2/RP exhibited an excellent H2 evolution rate of 2254.2 μmol g−1 h−1, which is 17.5 and 71.1-fold than that of pristine RP (129.1 μmol g−1 h−1) and FeCoS2 (31.7 μmol g−1 h−1), respectively. The analysis shows that bimetallic sulfides FeCoS2 can not only increase the electrochemically active surface area, decrease the H2 evolution overpotential and water contact angle of the composite, but also provide more photoinduced charges and reduce their transfer resistance, more importantly, the charge transfer between FeCoS2 and RP follows the S-scheme route, which can reserve the electrons and holes with higher the thermodynamic driving force. Further investigation shows that the activity of FeCoS2 is superior to monometallic sulfides FeS and CoS due to its synergistic effect between Fe and Co. This work provides new insights for constructing S-scheme RP-based heterojunction with high photocatalytic efficiency and stability.

Highly Sensitive Ethylene Sensors Based on Ultrafine Pd Nanoparticles-Decorated Porous ZnO Nanosheets and Their Application in Fruit Ripeness Detection

Ethylene is the most common ripening phytohormone in fruits, and excess ethylene can overripen the fruit. However, the in-field detection of ethylene is still limited. In this work, ultrafine Pd nanoparticles-decorated porous ZnO nanosheets (UPNP ZnO nanosheets) were conveniently synthesized through a facile solvent reduction method. The UPNP ZnO nanosheets were characterized using scanning electron microscopy, transmission electron microscopy, energy dispersive spectrum, X-ray diffraction and X-ray photoelectron spectroscopy. The ZnO nanosheets were uniformly coated with Pd nanoparticles. The size of the Pd nanoparticle was very small, with a diameter of approximately 2 nm. Due to the unique structure of the porous ZnO nanosheets and the excellent catalytic properties of the ultrafine Pd nanoparticles, the as-prepared samples showed very high sensing performance in ethylene detection. The lowest detection concentration was 10 ppb, which is the lowest detection limit to our knowledge. It has been proved that the decoration of ultrafine Pd nanoparticles can largely increase the relative percentage of chemisorbed oxygen and deficient oxygen, which are benefits for ethylene oxidation, and actually accelerate the process of the sensing reaction. Furthermore, the UPNP ZnO nanosheets can even be applied in fruit maturity detection. Using mangos as an example, our experiment revealed that the response of UPNP ZnO nanosheets to mangos at different maturity stages was quite different. This result suggests that our product has broad application prospects in monitoring fruit ripening stage.

Microencapsulation of Lead-Halide Perovskites in an Oil-in-Fluorine Emulsion for Cell Imaging.

The superior optical properties of lead-halide perovskites (LHPs) inspired significant research in cell imaging applications; many encapsulating processes have improved perovskite stabilities with comparable biosafety. Herein, facile solvent evaporation encapsulation based on an oil-in-fluorine emulsion for aqueous-stable and extremely nontoxic LHP microcapsules is described. Perfluorooctane dispersed the emulsifier fluorocarbon surfactant to form a continuous fluorine phase, while LHPs and polymethylmethacrylate (PMMA) were dispersed in 1,2-dichloroethane, then emulsified in the fluorine phase to form an oil-in-fluorine emulsion. CsPbBr3 microcapsules with a dense PMMA shell that protect fragile CsPbBr3 from the external environment and inhibit lead ion release were obtained after solvent evaporation. The CsPbBr3 microcapsules not only retained 91% of fluorescence intensity after exposure to water for 30 d but also possess extremely low cytotoxicity for MCF-7 cells. After exposure to 2 mg/mL of CsPbBr3 microcapsules for 48 h, the cell viability remained >90%. The intracellular uptake of CsPbBr3 microcapsules indicates its potential use in cell imaging.