Excellent Stability Research Articles

One-step chemical vapor deposition synthesis of Si NWs@C core/shell anodes without additional catalysts by the oxide-assisted growth mechanism for lithium-ion batteries.

Si NWs@C core/shell anodes for lithium-ion batteries were synthesized via a one-step environmental-pressure chemical vapor deposition (CVD) process utilizing nano-silicon and methane as raw materials. In this structure, the silicon nanowire core is obtained by controlling the temperature above 900 °C to catalyze the growth of nano-silicon particles coated with a natural oxide layer according to the oxide-assisted growth (OAG) mechanism, while the carbon as a protective coating shell is derived from methane cracking. In contrast to the conventional nanowire catalytic approach, this method obviates the addition of metal catalysts while ensuring a straightforward and scalable process. This Si NWs@C electrode displayed excellent electrochemical performance, exhibiting high reversible capacity (745.8 mA h g-1) and excellent cycling stability (91.3% after 100 cycles at 0.5 A g-1).

Optimized porous nanostructure of carbon fibers enabling excellent stability of Pt-based catalysts for oxygen reduction reaction

Facile synthesis of highly-dispersed Pt-based electrocatalysts on porous carbon supports with strong durability is extremely desirable for oxygen reduction reaction but remains challenging. The influence of pores in carbon supports on the stability and activity of catalysts is ambiguous and needs to be elucidated. Targeting this aim, herein, we prepared a series of carbon nanofibers with tunable pore diameter and specific surface area using the resorcinol-formaldehyde (RF) resins as a model system. Homogeneous composite precursors composed of RF resins and silica colloids were synthesized by the surfactant-assisted simultaneous polycondensation of RF resins and tetraethylorthosilicate (TEOS). The diameter of the pores induced by removal of silica could be controllable tailored through thermal treatment of the composite under various target temperatures. Pt3Co alloy nanoparticles loaded on the as-synthesized porous carbon nanofibers were prepared by an optimized wet-impregnation method. The experimental results indicated that the carbon nanofibers with pore size distribution focused on ∼1.27 nm and ∼2.34 nm provided the best stability without limiting current density decay, and negative shift of half-wave potential (E1/2) and mass activity (MA) loss of Pt after 20000 potential cycles are relatively mild. Conversely, negative shift of 21 mV, 15 mV and 22 mV in E1/2 and mass activity loss of 51.8%, 30.2% and 33.0% were observed for the Pt3Co nanoparticles supported on MC-60, MC-100 and MC-140 matrices which have pore size distribution focused on ∼2.73 nm, ∼2.73 nm as well as ∼4.66 nm, and ∼4.66 nm, respectively. This work demonstrates the importance of micropores and small mesopores for activity and long-term stability enhancement of carbon supported Pt-based electrocatalysts.

Crystallization management and defect passivation via additive engineering for efficient and stable carbon-based CsPbI2Br perovskite solar cells

Inorganic CsPbI2Br perovskite solar cells (PSCs) have attracted enormous interest due to their excellent thermal stability and immense potential for application in tandem solar cells. However, the rambunctious crystallization and poor film quality of inorganic CsPbI2Br perovskite are the main factors limiting their performance improvement. Herein, dibenzoylmethane (DBM), containing electron-rich and dual CO functional groups, as an efficient precursor additive, is first introduced to regulate the crystallization of CsPbI2Br perovskite while passivating its associated defects. After DBM modification, nucleation is accelerated and the crystallinity of CsPbI2Br film is improved, thus promoting the phase stability. Additionally, DBM can passivate uncoordinated Pb2+ defects, thereby significantly reducing non-radiative recombination, and can also decrease the energy level difference between CsPbI2Br/Carbon. As a result, when DBM additive is incorporated in the CsPbI2Br, the power conversion efficiency (PCE) of the device with the fluorine doped tin oxide glass (FTO)/SnO2/CsPbI2Br/Carbon structure is significantly improved to 13.46 %, an increase of nearly 13 % compared to the control device (11.72 %). The unpackaged devices exhibit excellent air and thermal stability, still remaining over 90 % of its initial PCE after aging for 500 h under ambient conditions, or continuous heating at 65 °C in glovebox for 500 h, respectively.

Developments of photo‐/electro‐catalysis based on covalent organic frameworks: A review

AbstractPhoto‐/electro‐catalysis has the characteristics of low cost, high performance, and zero pollution, which meet the policies on environment and energy. Covalent organic frameworks (COFs), a type of crystalline organic skeleton polymers, have been widely applied and investigated in the area of photo‐/electro‐catalysis owing to their advantages of large specific surface area, regular pore size, excellent stability, flexible structural design, and massive active sites. This article reviews the structural characteristics of COFs and the strategies for strengthening the photo‐/electro‐catalytic activity of COF materials. Subsequently, deep insights were put into the photo‐/electro‐catalysis application of COF materials. In the end, the development prospects and challenges faced by COF materials in photo‐/electro‐catalysis are discussed.

Enhanced Charge Transfer in Quasi-2D Perovskite by Formamidinium Cation Gradient Incorporation for Efficient and Stable Solar Cells.

Quasi-2D perovskites have attracted much attention in perovskite photovoltaics due to their excellent stability. However, their photoelectric conversion efficiency (PCE) still lags 3D counterparts, particularly with high short-circuit current (JSC) loss. The quantum confinement effect is pointed out to be the sole reason, which introduces widened bandgap and poor exciton dissociation, and undermines the light capture and charge transport. Here, the gradient incorporation of formamidinium (FA) cations into quasi-2D perovskite is proposed to address this issue. It is observed that FA prefers to incorporate into the larger n value phases near the film surface compared to the smaller n value phases in the bulk, resulting in a narrow bandgap and gradient structure within the film. Through charge dynamic analysis using in situ light-dark Kelvin probe force microscopy and transient absorption spectroscopy, it is demonstrated that incorporating 10% FA significantly facilitates efficient charge transfer between low n-value phases in the bulk and high n-value nearby film surface, leading to reduced charge accumulation. Ultimately, the device based on (AA)2(MA0.9FA0.1)4Pb5I16, where AA represents n-amylamine renowned for its exceptional environmental stability as a bulky organic ligand, achieves an impressive power conversion efficiency (PCE) of 18.58% and demonstrates enhanced illumination and thermal stability.

Preparation of Nonlinear Structure Poly(glycolic acid) with High Toughness, Excellent Hydrolysis Stability, and Foaming Performance

Preparation of Nonlinear Structure Poly(glycolic acid) with High Toughness, Excellent Hydrolysis Stability, and Foaming Performance

Advanced Hierarchical Biomorphous Silicon Carbide Monoliths

Porous silicon carbide (SiC) has attracted considerable attention in the field of cellular ceramics for a variety of applications such as catalyst supports, filters, or in the biomedical field due to its excellent structural properties, mechanical strength, and chemical stability. However, SiC has certain limitations due to high‐temperature profiles and costly manufacturing methods. Therefore, it is investigated that porous biomorphic silicon carbide monoliths using a powder blend of paper‐derived carbon fibers, phenolic resin, and silicon, resulting in comparatively low sintering temperatures (T = 1300 to 1550 °C) and good mechanical strength. This near‐net‐shape process uses low‐cost raw materials and enables the production of silicon carbides with high open porosity (P = 51.48% to 68.28%) and low shrinkage. The influence of different amounts of carbon sources (Cfibers and Cresin) on the mechanical (4‐point bending) and thermal properties (laser flash method) is investigated. In addition, to improve the pressure gradients, macrochannels with multiple layers of sacrificial polymer lattices are incorporated, resulting in hierarchical structures with high permeability. Thus, this advanced biomimetic approach offers great potential for structured cellular ceramics with tailored properties for biomedical, catalyst support, or nuclear fuel cladding materials.

Rational design of hollow C@SnS2/SnS@C cubes with N-doping to realize stepwise sodium storage induced structural stability for highly stable cycling performance

Current application of SnS2-based anodes in sodium-ion batteries fails to meet the demand for higher Na+ storage capacity due to the structural pulverization induced by significant volume changes during cycling. Herein, a novel composite of hollow C@SnS2/SnS@C cubes with excellent diffusion kinetics and structural stability from stepwise Na+ storage is designed. The SnS with gentle pseudocapacitive reaction acts as the self-supporter to prevent the collapse of SnS2/SnS heterostructure during the Na+ insertion/extraction. Together with the clamping of double carbon layers and hollow construction, the volume change caused structural instability in heterostructure is effectively alleviated. The rapid transport of electrons and ions within the built-in electric field of heterostructure endows the composite an excellent diffusion kinetics, which is generated from the narrow bandgap and outstanding Na+ absorption of heterostructure according to the first-principle calculation. Thus, the as-prepared composite maintains a remarkable capacity of 547.9 mAh g−1 after 200 cycles at current density of 0.5 A g−1. Even a capacity of 502.5 mAh g−1 with a low attenuation rate of 0.035 % per cycle is achieved at 2 A g−1 after 1000 cycles. The work proposes an effective approach to achieve effective Na + storage of SnS2-based anodes with long-lasting structural stability.

One-Pot Synthesis of Nanoflower-Like Zn2SnS4 as Nanozymes for Highly Sensitive Electrochemical Detection of H2O2 Released by Living Cells.

The sensitive and reliable nanozyme-based sensor enables the detection of low concentrations of H2O2 in biological microenvironments, it has potential applications as an in-situ monitoring platform for cellular H2O2 release. The uniformly dispersed bimetallic sulfide (Zn2SnS4) nanoflowers were synthesized via a one-pot hydrothermal method and the two kinds of metal ions can serve as morphology and structure directing agents for each other in the synthetic process. The nanoparticles were utilized as nanozyme materials to fabricate a novel electrochemical sensor, and it exhibits a distinct electrochemical response towards H2O2 with excellent stability and detection capability (with a minimum detection limit of 1.79 nM (S/N=3)), the excellent characteristics facilitate the precise detection of low concentrations of H2O2 in biological microenvironments. Use the macrophages differentiated from leukemia THP-1 cells as a representative sensing model, the sensor was successfully utilized for real-time monitoring of the release of H2O2 induced by living cells, which has significant potential applications in clinical diagnosis and cancer treatment.

Superlative Porous Organic Polymers for Photochemical and Electrochemical CO2 Reduction Applications: From Synthesis to Functionality.

To mimic the carbon cycle at a kinetically rapid pace, the sustainable conversion of omnipresent CO2 to value-added chemical feedstock and hydrocarbon fuels implies a remarkable prototype for utilizing released CO2. Porous organic polymers (POPs) have been recognized as remarkable catalytic systems for achieving large-scale applicability in energy-driven processes. POPs offer mesoporous characteristics, higher surface area, and superior optoelectronic properties that lead to their relatively advanced activity and selectivity for CO2 conversion. In comparison to the metal organic frameworks, POPs exhibit an enhanced tendency toward membrane formation, which governs their excellent stability with regard to remarkable ultrathinness and tailored pore channels. The structural ascendancy of POPs can be effectively utilized to develop cost-effective catalytic supports for energy conversion processes to leapfrog over conventional noble metal catalysts that have nonlinear techno-economic equilibrium. Herein, we precisely surveyed the functionality of POPs from scratch, classified it, and provided a critical commentary of its current methodological advancements and photo/electrochemical achievements in the CO2 reduction reaction.

Enhanced long-term performance of ureteral stents with functional coating: Combating bacterial adhesion and inhibiting encrustation

Long-term indwelling ureteral stents in urology surgeries often lead to severe encrustation and challenging clinical complications, necessitating an effective medical response. Although many researchers have started with antibacterial, anti-fouling and other aspects, the lack of direct urinary pertinence or develop drug resistance have not really improved the current situation of crust. Therefore, while giving full play to the excellent properties of coated anti-bacterial adhesion, it is still a challenging problem to ensure that it can be effectively applied to ureteral stents and urinary tract environment. Herein, this work proposes a practical functional coating to inhibit encrustation, achieved by incorporating the urinary crystal inhibitor citric acid to crosslink the polyvinylpyrrolidone with hydrophilic lubrication properties (PVP/CA). The coating based on charge interaction has excellent stability (peel strength up to 600 N/m) excellent wettability (contact angle reduced by 60°), lubricity (friction coefficient reduced by 4 times) and biocompatibility. More importantly, the synergistic anti-bacteria adhesion (>90 %) and inhibition of urinary tract crystallization properties of the coated ureteral stent demonstrate superior performance in preventing encrustation over a 4-week period in an in vitro model. This innovative coating strategy holds promising prospects for ureteral stents, offering a potential solution to alleviate pain in urological patients.

Manipulating 2D Membrane Interlayer Channels with Accelerated Mass-Transfer Behavior to Boost Solar Desalination.

The scarcity of fresh water necessitates sustainable and efficient water desalination strategies. Solar-driven steam generation (SSG), which employs solar energy for water evaporation, has emerged as a promising approach. Graphene oxide (GO)-based membranes possess advantages like capillary action and Marangoni effect, but their stacking defects and dead zones of flexible flakes hinders efficient water transportation, thus the evaporation rate lag behind unobstructed-porous 3D evaporators. Therefore, fundamental mass-transfer approach for optimizing SSG evaporators offers new horizons. Herein, a universal multi-force-fields-based method is presented to regularize membrane channels, which can mechanically eliminate inherent interlayer stackings and defects. Both characterization and simulation demonstrate the effectiveness of this approach across different scales and explain the intrinsic mechanism of mass-transfer enhancement. When combined with a structurally optimized substrate, the 4Laponite@GO-1 achieves evaporation rate of 2.782kg m-2 h-1 with 94.48% evaporation efficiency, which is comparable with most 3D evaporators. Moreover, the optimized membrane exhibits excellent cycling stability (10 days) and tolerance to extreme conditions (pH 1-14, salinity 1%-15%), verifies the robust structural stability of regularized channels. This optimization strategy provides simple but efficient way to enhance the SSG performance of GO-based membranes, facilitating their extensive application in sustainable water purification technologies.

Designed Additive to Regulated Crystallization for High Performance Perovskite Solar Cell

It is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high‐quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE·PbI2 and DA·PbI2 retard perovskite crystallization process for high‐quality film formation, which was monitored through in situ UV‐vis and PL tests. By using DFA additives, we prepared perovskite films with high‐quality and low defects. Finally, a champion PCE of 25.28% was achieved with excellent environmental stability, which retained 95.75% of the initial PCE after 1152 h at 25 °C under 25% RH.

Electro‐Induced Self‐Reduction TiO2 in Viologen‐Based Ionogels for Multi‐Color Electrochromic Displays

AbstractReflective electrochromic (EC) technology is expected to e‐paper display field, and integrating optical reflective electrolyte as the optical reflective layer is a common strategy for constructing reflective EC devices. Compositing inorganic particles and electrolytes is one of the simplest and most efficient composite methods, but these composite electrolytes usually cannot perform well together in terms of both optical and electrochemical properties. Herein, the TiO2 nanoparticles are added to the ethyl viologen‐based ionogel (T‐EVG, one typical kind of EC/electrolyte) to have the highest visible light reflectivity and the best electrochemical performance compared with SiO2, Al2O3, and ZnO nanoparticles, which is attributed to the electro‐induced self‐reduction TiO2 produced in T‐EVG during EC cycling. Meanwhile, the corresponding EC devices can display red, green, and blue, and have high optical contrast (CIE Lab: ΔE>38), fast switching spend (<4 s, the fastest is 5 Hz), ultra‐low power density (<4.0 mW cm−2), and excellent cycling stability (>85% retained after 10 000 cycles). Finally, a simple 3×3 pixelated EC display array is prepared, and single‐ and multi‐point (including diagonal points) multi‐color display effects are realized through active‐matrix driving and high‐frequency refresh, demonstrating its application value in the high‐performance e‐paper display.

3D Printed P(VdF‐HFP)/SBA‐15 composite‐based gel polymer electrolyte versus commercial celgard: A comparative investigation on thermal stability and electrochemical performance for lithium‐ion battery application

AbstractThe current work reports on tailoring of 3D printed gel polymer electrolyte (GPE) employing poly(vinylidene fluoride‐co‐hexafluoropropylene) P(VdF‐HFP) as the host matrix and mesoporous Santa Barbara Amorphous‐15 (SBA‐15) mesoporous sieve as ceramic filler. Further, this work envisages an investigation on its physicochemical properties, thermal shrinkage behavior, and electrochemical performance. An effort has been undertaken to formulate 3D printable P(VdF‐HFP)/SBA‐15 composite‐based GPE ink with suitable rheological properties. The breath figure method is followed to investigate the influence of 1‐methyl‐2‐pyrrolidinone (NMP)/tetrahydrofuran (THF) mixture as a solvent on the porosity of 3D printed GPE, through which enhanced porosity is evident from scanning electron microscopy (SEM) analysis. The morphological analysis further confirms the hybrid porous structure facilitated by the addition of SBA‐15 into the P(VdF‐HFP) matrix. The 3D printed P(VdF‐HFP)/SBA‐15 (10%) composite‐based GPE shows promising ionic conductivity in the order of 0.2 × 10−4 S/cm at room temperature and demonstrates excellent dimensional thermal stability up to 175°C. The electrochemical measurement of 3D printed GPE is tested separately using 3D printed cathode half‐cell (3D printed LFP vs. Li+) and 3D printed anode half cell (3D printed LTO vs. Li+) with GPE as separator. Further, also tested with conventionally prepared electrode and the coin cell studies show discharge capacity of 3D printed P(VdF‐HFP)/SBA‐15 (10%) composite‐based GPE is comparable to commercial celgard separator. All these features speculate that the 3D printed fabricated in the current work may find potential application in lithium‐ion battery.

Electron Beam-Supported Fabrication of Biocompatible Silver/iota-Carrageenan for Wound Healing Application.

Silver nanoparticles (AgNPs) are a potent antibacterial agent, especially when used to treat bacteria that are multidrug resistant. However, it is challenging to eliminate the hazardous reducing agents that remain in AgNPs produced by the conventional chemical reduction process. To overcome these challenges, the presented research demonstrates the fabrication of AgNPs using iota-carrageenan (ι-carra) as a carbohydrate polymer using electron beam (EB) irradiation. Well-characterized ι-carra@AgNPs have a face-centered cubic (FCC) structure with spherical morphology and an average size of 26 nm. Herein we explored the approach for fabricating ι-carra@AgNPs that is suitable for scaling up the production of nanoparticles that exhibit excellent water stability. Further, the optimized ι-carra@AgNPs exhibited considerable antibacterial activity of 40% and 30% inhibition when tested with Gram-negative Escherichia coli ATCC 43895 and Gram-positive Staphylococcus aureus (S. aureus) (ATCC 6538), respectively, and low cytotoxicity at 10-50 μg/mL. To establish the potential biomedical application, as proof of the concept, the ι-carra@AgNPs showed significant antibiofilm activity at 20 μg/mL and also showed 95% wound healing abilities at 50 μg/mL compared to the nontreated control groups. Electron beam assisted ι-carra@AgNPs showed significant beneficial effects against specific bacterial strains and may provide a guide for the development of new antibacterial materials for wound dressing for large-scale production for biomedical applications.

Synergistic polarization engineering of dielectric towards low-voltage high-mobility solution-processed ultraflexible organic transistors

The emerging wearable skin-like electronics require the ultra-flexible organic transistor to operate at low voltage for electrical safety and energy efficiency and simultaneously enable high field-effect mobility to ensure the carrier migration ability and the switching speed of circuits. However, the currently reported low-voltage organic transistors generally present low mobility, originating from the trade-off between molecular polarity and surface polarity of the dielectrics. In this work, the orientation polarization of the dielectric is enhanced by introducing a flexible quaternary ammonium side chain, and the surface polarity is weakened by the shielding effect of the nonpolar methyl groups on the polar nitrogen atom. The resulting antisolvent QPSU dielectric enables the high-dielectric constant up to 18.8 and the low surface polarity with the polar component of surface energy only at 2.09 mJ/m2. Such a synergistic polarization engineering between orientation polarization and surface polarity makes the solution-processed ultraflexible transistors present the ultralow operational voltage down to −3 V, the ultrahigh charge-carrier mobility up to 8.28 cm2 V−1 s−1 at 1 Hz, excellent cyclic operational stability and long-term air stability. These results combined with the ultrathin thickness of transistor as low as 135 nm, the ultralight mass of 0.5 g/m2, the conformal adherence capability on human skin and 1-μm blade edge, and the strong mechanical robustness with stable electrical properties for 30,000 bending cycles, open up an available strategy to successfully realize low-voltage high-mobility solution-processed organic transistor, and presents the potential application of QPSU dielectric for the next-generation wearable imperceptible skin-like electronics.

Designed Additive to Regulated Crystallization for High Performance Perovskite Solar Cell.

It is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high-quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE·PbI2 and DA·PbI2 retard perovskite crystallization process for high-quality film formation, which was monitored through in situ UV-vis and PL tests. By using DFA additives, we prepared perovskite films with high-quality and low defects. Finally, a champion PCE of 25.28% was achieved with excellent environmental stability, which retained 95.75% of the initial PCE after 1152 h at 25 °C under 25% RH.

Development and Evaluation of a Novel Antibacterial Wound Dressing: A Powder Preparation Based on Cross-Linked Pullulan with Polyhexamethylene Biguanide for Hydrogel-Transition in Advanced Wound Management and Infection Control

As antibiotic resistance increasingly undermines traditional infection management strategies, there is a critical demand for innovative wound care solutions that address these emerging challenges. This study introduces a novel antibacterial wound dressing based on Cross-Linked Pullulan (Pul) and Polyhexamethylene Biguanide (PHMB) for enhanced wound management and infection control. The dressing’s adsorption rate reached 200% of its original weight within 30 min, exceeded 300% after 5 h, and exhibited significant non-Newtonian fluid properties. The dressings were able to release the loaded medication completely within 20 min; additionally, the dressing demonstrated significant antibacterial activity against a broad spectrum of bacteria. Significantly, the therapeutic effects of the Pul-PHMB/GP dressing were evaluated in a mouse model. Compared to untreated wounds, wounds treated with Pul-PHMB/GP exhibited a significant gelation process within 5 min post-treatment and showed a significant increase in wound healing rate within 12 days. This powder preparation overcomes the limitations associated with liquid and gel dressings, notably in storage and precise application, preventing the premature expansion or dissolution often caused by PHMB in high-humidity environments. The powder form can transform into a gel upon contact with wound exudate, ensuring accurate coverage of irregular wounds, such as those from burns or pressure sores, and offers excellent chemical and physical stability in a dry state, which facilitates storage and transport. This makes the dressing particularly suitable for emergency medical care and precision therapy, significantly improving the efficiency and adaptability of wound treatment and providing robust support for clinical treatments and emergency responses.

Interface-constrained catalytic hairpin assembly permits highly sensitive SERS signaling of miRNA.

The rapid and precise monitoring of peripheral blood miRNA levels holds paramount importance for disease diagnosis and treatment monitoring. In this study, we propose an innovative research strategy that combines the catalytic hairpin assembly reaction with SERS signal congregation and enhancement. This combination can significantly enhance the stability of SERS detection, enabling stable and efficient detection of miRNA. Specifically, our paper-based SERS detection platform incorporates a streptavidin-modified substrate, biotin-labeled catalytic hairpin assembly reaction probes, 4-ATP, and primer-co-modified gold nanoparticles. In the presence of miRNA, the 4-ATP and primer-co-modified gold nanoparticles can specifically recognize the miRNA and interact with the biotin-labeled CHA probes to initiate an interfacial catalytic hairpin assembly reaction. This enzyme-free high-efficiency catalytic process can accumulate a large amount of biotin on the gold nanoparticles, which then bind to the streptavidin on the substrate with the assistance of the driving liquid, forming red gold nanoparticle stripes. These provide a multitude of hotspots for SERS, enabling enhanced signal detection. This innovative design achieves a low detection limit of 3.47 fM while maintaining excellent stability and repeatability. This conceptually innovative detection platform offers new technological possibilities and solutions for clinical miRNA detection.