Strong Electrostatic Interactions Research Articles

A smartphone-assisted electrochemiluminescent biosensor for highly sensitive detection of miRNA-21 based on Ru(bpy)2(L)4+@MOF-5.

A smartphone-assisted electrochemiluminescence (ECL) strategy based on Ru(bpy)2(L)4+ as chromophores confined with metal - organic frameworks (Ru(bpy)2(L)4+@MOF-5) for the signal-amplified detection of miRNA-21 was developed. We synthesized a derivative of tris(2,2'-bipyridyl)ruthenium(II) complex (Ru(bpy)2(L)4+) with high charges, which can be loaded into the MOF-5 by strong electrostatic interaction to prevent from leakage. In addition, nucleic acid cycle amplification was used to quench the signal of Ru(bpy)2(L)4+@MOF-5 by ferrocene. This method was applied to detect the concentration of miRNA-21 ranging from 1.0 × 10-14-1.0 × 10-9 M with a low LOD of 7.2 fM. This work demonstrated the construction of a signal quenching strategy ECL biosensor for miRNA using Ru(bpy)2(L)4+@MOF-5 systems and its application in smartphone-assisted ECL detection.

Dual‐Ion Co‐Insertion Engineering for Kinetics Enhancement and Stress Regulation in Cu3VS4 Toward Durable Magnesium/Lithium Hybrid Batteries

AbstractRechargeable magnesium batteries (rMBs) have tremendous development prospects in the field of energy storage, however, the strong electrostatic interactions induced by divalent Mg2+ give rise to the sluggish diffusion kinetics. Herein, the dual ion co‐intercalation strategy is proposed to expedite ion migration in Cu3VS4, achieving elevated specific capacity, transcendent rate capability, and ultra‐stable cycling capability. Kinetic analyses combined with DFT calculations indicate that the dual‐ion co‐insertion can fast charge transfer, reduce the diffusion barrier of Mg2+and optimize the reaction kinetics. Finite element simulations quantitatively verify that dual ion co‐intercalation contributes to alleviating magnesiation/lithiation‐induced stress in the shell layer and maintains structural integrity from a mechanical standpoint. Ex situ characterizations profoundly illustrates the multistep magnesium/lithium storage mechanisms and the evolution of structure. The proposed cation co‐intercalation strategy not only holds promise in opening new insights for high‐performance, continuously stable rMBs, but also provides inspiration for multivalent battery systems.

Constructing type II heterojunction of 2D/1D Pg-C3N4/Ag3VO4 nanocomposite with high interfacial charge separation for boosting photocatalytic CO2 reduction under solar energy

The well-designed, template-free synthesis of 2D protonated g-C3N4 nanosheets (Pg-C3N4) coupled with novel 1D Ag3VO4 nanorods has been investigated to construct 2D/1D interface heterostructures with strong electrostatic interactions between the positively charged 2D Pg-C3N4 nanosheets and the negatively charged 1D Ag3VO4 nanorods. The coupling of Pg-C3N4 and Ag3VO4 with desirable characteristics resulted in a 2D/1D interface heterojunction with a type II charge carrier transfer mechanism, effectively maintaining and utilizing charge carriers. The 2D/1D Pg-C3N4/Ag3VO4 exhibited remarkable photocatalytic performance for CO2 conversion with H2O, resulting in maximum CH4 and dimethyl ether (DME) production of 352.3 and 130.9 µmol/g-cat, respectively. A quantum yield of 0.23% for CH4 generation was achieved over the 2D/1D Pg-C3N4/Ag3VO4, which was 2.9 and 1.4 times higher than that of the Pg-C3N4 and Ag3VO4 samples, respectively. The improvement in photocatalytic performance primarily stems from the effective interaction between Pg-C3N4 and ternary Ag3VO4, leading to enhanced transfer and separation of photoinduced charge carriers through the creation of a type II heterojunction. The findings of this study are useful in designing template-free heterojunctions for photocatalytic CO2 conversion and other solar energy applications.

Characterization of NK-lysin A, a potent antimicrobial peptide from the zebrafish Danio rerio

Antimicrobial peptides (AMPs) are important players of the innate immune system with a major role in the defense against invading pathogens. AMPs belonging to the family of saposin-like proteins (SAPLIPs) include the porcine NK-lysin and the human granulysin. In the zebrafish Danio rerio, transcript analyses of NK-lysin encoding genes have been reported, but a biochemical characterization at the protein level are missing so far. Here, we present the recombinant expression, purification, and characterization of one of these homologs, namely of NK-lysin A (DaNKlA). To remove the affinity tag from DaNKlA, we made use of a self-splicing intein. Recombinant DaNKlA depolarized liposomes over a broad pH range and showed a preference for negatively charged lipids. DaNKlA inhibited the growth of and killed different Gram-positive and Gram-negative bacteria, including the fish pathogenic bacterium Vibrio anguillarum, by membrane permeabilization but displayed substantially lower activity against yeast cells. Structural modelling and bioinformatic comparison of DaNKlA with characterized SAPLIPs suggest membrane destabilization accompanied by strong electrostatic interactions as the mode of action.

Supramolecular assembly strategy of modified starch chains for achieving recyclable emulsion biocatalysis within a narrow pH range

Stimuli-responsive Pickering emulsions are promising in biocatalysis for their ease of product separation and emulsifier recovery. However, pH responsiveness, though simple and cost-effective, faces challenges in precise control and narrow transition ranges, limiting its use in enzymatic catalysis. Herein we introduced amorphous octenyl succinic anhydride-modified debranched starch chains (Am-OSA-St) to control emulsion properties within a pH range suitable for enzymatic catalysis. By adjusting the OSA group density and molecular weight, Am-OSA-St allowed emulsions to transition reversibly between pH 7.3 and 5.5 and enabled self-recycling through supramolecular self-assembly. Employing molecular dynamics simulations and physicochemical characterization, we elucidated the control mechanism of oil-water interfaces via the microstructure transformation of Am-OSA-St. The findings revealed that protonation of carboxylate groups disrupted the charge balance and polarity of starch chains, leading to strong electrostatic and van der Waals interactions that drove self-assembly. This entanglement caused starch chains in the aqueous phase to “drag” those at the oil-water interface, moving them into the aqueous phase and forming micelles. These micelles, with a hydrophobic interior and hydrophilic exterior, prevented re-adsorption. Testing with Candida antarctica Lipase B (CALB) and N-acetylneuraminic lyase showed that the pH-regulated emulsion system maintained excellent efficiency and cycling stability in mild conditions.

Oxygen-deficient NH4V4O10 cathode with Ag quantum dots and interlayer Ag+ towards high-performance aqueous zinc ion batteries

Herein, oxygen-deficient NH4V4O10 micro-flowers with loaded Ag quantum dots and pre-intercalated Ag+ (NVO-Ag) for aqueous zinc ion battery (AZIB) cathode materials were successfully synthesized by a one-step hydrothermal method. The reversible redox reaction between Ag+ and Ag quantum dots, and the abundant Zn2+ storage sites from oxygen vacancies provided capacity contributions for NVO-Ag. Meanwhile, the loaded Ag quantum dots, pre-intercalated Ag+ and introduced oxygen vacancies synergistically optimized the electronic structure and distribution of NVO-Ag, promoting the transport of electrons in NVO-Ag. The pre-intercalated Ag+ could also replace the NH4+ in the interlayer of NH4V4O10, weakening the repulsion between the interlayer NH4+ and Zn2+, which achieved rapid Zn2+ diffusion kinetics. Moreover, the abundant oxygen vacancies in NVO-Ag could alleviate the strong electrostatic interaction between Zn2+ and V-O framework, boosting the transmission of Zn2+ in NVO-Ag. Finally, the structural stability of NH4V4O10 micro-flowers was improved due to the high bonding strength between Ag+ and V-O layers. Benefiting from the above effects, NVO-Ag-100 achieved excellent capacity performance (387.2 mA h/g at 0.5 A/g), rate performance (178.9 mAh/g at 12 A/g) and cycle stability (91.7 % capacity retention after 1700 cycles at 8 A/g). This work provided effective ideas to achieve high-performance AZIB cathode materials.

Effects of 2-ethylbutyric acid, 2-ethyl-1-butanol, and 3-methylpentane on the micellization thermodynamics and physicochemical properties of HS 15 and TW 80 micelles based on differences in functional groups

Herein, we investigated the effects of 2-ethylbutyric acid, 2-ethyl-1-butanol, and 3-methylpentane, each possessing varying functional groups, on polyoxyl 15 hydroxystearate (HS 15) and polysorbate 80 (TW 80) micelles. Initially, the critical micelle concentration (CMC) for both systems was determined. Subsequent measurements included the particle size, zeta potential, cloud point, micropolarity, number of aggregates, and fluorophore release profile. Finally, the number of hydrogen bonds was confirmed through molecular docking technology. Results showed distinct effects of different functional groups on TW 80 and HS 15 micelles, exhibiting a decreasing trend of CMC, Amin, Gmin, particle size, and polydispersity index (PDI) with increased functional group polarity, alongside increased zeta potential, decreased cloud point, enlarged hydrophobic region, and rapid fluorophore quenching. In particular, acids with carboxyl groups exhibited enhanced stability with HS 15 and TW 80 micelles owing to differences in polarity, solubilization sites, and intermolecular forces. Using tanshinone extract as a model drug, the study explored HS 15 and TW 80 micelles as drug carriers, and results indicated that 2-ethylbutyric acid micelles exhibited better bacterial inhibition against Staphylococcus aureus. Considering that the surface of bacteria was negatively charged, the positively charged nanoparticles exhibited strong electrostatic interactions with the bacteria, which exerted a superior antibacterial effect. In summary, 2-ethylbutyric acid micelles displayed the smallest CMC, Amin, Gmin, particle size, and PDI, along with a positive charge, highlighting the potential application of 2-ethylbutyric acid.

Organic-Inorganic Coupling Strategy: Clamp Effect to Capture Mg2+ for Aqueous Magnesium Ion Capacitor.

The rapid transport kinetics of divalent magnesium ions are crucial for achieving distinguished performance in aqueous magnesium-ion battery-based energy storage capacitors. However, the strong electrostatic interaction between Mg2+ with double charges and the host material significantly restricts Mg2+ diffusivity. In this study, a new composite material, EDA-Mn2O3, with double-energy storage mechanisms comprising an organic phase (ethylenediamine, EDA) and an inorganic phase (manganese sesquioxide) was successfully synthesized via an organic-inorganic coupling strategy. Inorganic-phase Mn2O3 serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of Mn2O3 as an elastic matrix, works synergistically with Mn2O3, and utilizes bidentate chelating ligands to capture Mg2+. The robust coordination effect of terminal biprotonic amine in EDA enhances the structural diversity and specific capacity characteristics of the composite material, as further corroborated by density functional theory (DFT) calculations, ex-situ XRD, XPS, and Raman spectroscopy. As expected, an aqueous magnesium ion capacitor with EDA-Mn2O3 serving as the cathode can reach 110.17 Wh/kg. This study aimed to explore the practical application value of organic‒inorganic composite electrodes with double-energy storage mechanisms.

Microscopic insights into water wetting behaviors and physical origin on α-quartz exposed to varying underground gas species

Understanding the wetting behaviors of water on quartz surfaces and underlying mechanisms when immersed in varying gas environments is crucial for the efficient implementation of geological engineering projects, such as H2gas geo-storage, natural gas production, and greenhouse gas geo-sequestration.In the present work, classical molecular dynamic (MD) simulations are applied to investigate the deionized (DI) water and brine (with a salinity of ∼1.5 M and ∼3.5 M) wettability of quartz surfaces and interfacial properties in the presence of various gas species (i.e., H2, CH4, and CO2) under a typical geological condition (333K and 20 MPa). The inherent mechanisms regulating surface wettability are revealed by Young’s equation and interaction energy analysis. Thanks to the strong electrostatic interaction, water forms several adsorption layers on quartz surfaces, whereas gas molecules are mainly adsorbed on the region where the water is not accessible through van der Waals interaction. The presence of salt ions has negligible effects on water and gas distributions as they tend to be depleted from the surface area. When immersed in varying gas species, the contact angle (CA) of water on quartz follows an order of CO2 > CH4 > H2due to the faster decay in gas–solid interaction compared with gas–water interaction. Increasing salt ions is generally unfavorable for the spreading of water on quartz surfaces regardless of gas types resulting in a larger CA value, which is primarily attributed to the augmented gas–water interfacial tension. This study provides important insights into the wettability behaviors of water on quartz surfaces under varying gas conditions and deepens the understanding of the molecular origin of wetting characteristics on quartz surfaces, which is beneficial for explaining relevant phenomena and leading engineering practice.

FRAP analysis of peptide diffusion in extracellular matrix mimetic hydrogels as an in vitro model for subcutaneous injection

Subcutaneous (SC) injection is a common route of administration for drug compounds with poor oral bioavailability. However, bioavailability is often variable and incomplete, and there is as yet no standard accepted medium for simulation of the human SC environment. In this work we evaluate a FRAP based method for quantitative determination of local self-diffusion coefficients within extracellular matrix (ECM) mimetic hydrogels, potentially useful as in vitro models for drug transport in the ECM after SC injection. Gels were made consisting of either agarose, cross-linked collagen (COL) and hyaluronic acid (HA) or cross-linked HA. The diffusivities of uncharged FITC-dextran (FD4), the highly charged poly-lysine (PLK20) and poly-glutamic acid (PLE20) as well as the GLP-1 analogue exenatide were determined within the gels using FRAP. The diffusion coefficients in uncharged agarose gels were in the range of free diffusion in PBS. The diffusivity of cationic PLK20 in gels containing anionic HA was substantially decreased due to strong electrostatic interactions. Peptide aggregation could be observed as immobile fractions in experiments with exenatide. We conclude that the FRAP method provides useful information of peptides’ interactions and transport properties in hydrogel networks, giving insight into the mechanisms affecting absorption of drug compounds after subcutaneous injection.

Theoretical and experimental studies of cephalexin adsorption on aluminium as a new alternative of removal from wastewater

ABSTRACT Cephalexin (CPX) is an antibiotic widely used to treat many infections. CPX has become an emerging pollutant present in wastewater. On the other hand, it is well known that organic compounds can be adsorbed over metal surfaces when the metal is in active state such as when it is rusting. This work proposes an alternative for the elimination of CPX from wastewater, applying electrochemical principles using a conventional and cheap substrate, aluminium. The first part consisted of obtaining the active states of aluminium electrodes carrying out voltametric curves at different pH (4, 7 and 9) to find the particular condition of interaction between CPX and metal surface. The potential was used in the potentiostatic tests to set the activation potential of metal at different times. After the treatment, electrolyte solutions were analysed using UV-vis spectra, and the aluminium surfaces were studied by optical micrographs and X-ray diffraction. In addition, aluminium-CPX interactions were corroborated by quantum-chemical calculations and adsorption isotherms. All results indicate that it was possible for the CPX removal at basic pH conditions, where the molecule adsorption on the aluminium substrate occurs due to a strong electrostatic interaction.

Polyvinylimidazole-Based Cryogel as an Efficient Tool for the Capture and Release of Oleuropein in Aqueous Media.

A polyvinylimidazole-based cryogel is presented as a pioneering solution for efficient extraction and release of partially water-soluble polyphenols from olive byproducts. Specifically, oleuropein was used as model molecule to evaluate its recovery from water. The material merges the properties of interconnected cryogel structure in adsorbing molecules via fast diffusion flux, with the strong electrostatic interactions acted by imidazole moiety. Such cryogel achieves effective oleuropein binding likely through hydrogen bonding and π-π interactions. Comprehensive assessments of static adsorption kinetics, isotherms, and desorption kinetics underscore the cryogel's efficacy in oleuropein extraction and release, highlighting its pivotal role in valorizing olive wastewater through sustainable biotechnological applications.

Improved moisture barrier and mechanical properties of rice protein/sodium alginate films for banana and oil preservation: Effect of the type and addition form of fatty acid

Attenuating the moisture sensitivity of hydrophilic protein/polysaccharide-based films without impairing other properties remains a challenge. Fatty acid dispersed in Pickering emulsion was proposed to overcome such issue. An increase in fatty acid chain length slightly reduced the water vapor permeability (WVP) of emulsion films. As the number of fatty acid double bonds increased from 0 to 1, the WVP of emulsion films was significantly decreased by 14.02% while mechanical properties were significantly enhanced. More hydrogen bonds and stronger electrostatic interactions in the presence of fatty acids were observed by molecular dynamics simulation. The weight loss of bananas coated with oleic acid-incorporated film-forming emulsion was 6.81% lower than that of uncoated group after 4 days, and the corresponding film was more effective to delay oil oxidation than the commercial polypropylene film, indicating that the film is a promising alternative to food coating and packaging material.

Water sorption behavior of poly(norbornene)-based anion exchange polyelectrolytes: Experiments and simulation

Poly(norbornene)s (PNBs) are great potential candidates for anion exchange polyelectrolytes (AEPs), however, PNBs-based AEPs usually suffer from excessive water sorption. Herein, the underlying mechanism behind high water sorption was proposed by using the quaternized PNBs as a model AEP. With a moderate ionic content of 2.15 mmol/g, the hydrogenated AEP has a high water uptake of 253 % at 25 °C, which is caused by heterogeneous quaternization and weak interchain interactions. When the brominated AEP was immersed in trimethylamine aqueous (TMA/H2O) solution, TMA penetrates tightly packed polymer chains, seriously destroying vdW interchain interactions. Subsequently, the quaternized cationic groups induce spontaneous water sorption. Although ionic moieties possess strong interchain electrostatic interactions, the solid AEPs restrict polymer chains to form highly cohesive domains for resisting water sorption. Additionally, carbon–carbon double bonds in the PNBs preferentially interact with TMA/H2O, further increasing water uptake. This work provides theoretical guidance for preparing high-performance AEPs based on all-hydrocarbon aliphatic backbones.

Effect of stacking pattern of multilayered polyetheretherketone/boron nitride composites on the mechanical and thermal properties: Experiments and molecular dynamics simulations

The effect of stacking patterns in multilayered polyetheretherketone (PEEK)/boron nitride (BN) composites was investigated to improve the thermal conductivity and mechanical properties. The thick PEEK and BN layers in the multilayered composite were the best multilayer structure, resulting in high mechanical properties and in-plane thermal conductivity due to the many strong electrostatic interaction sites between boron nitride nanosheets (BNNSs). Molecular dynamics simulations were used to clarify the enhanced mechanism of multilayered structure on thermal conductivity. The multilayered structure with combinations of PEEKs and thick BN layers composed of large BNNSs led to the optimization of heat transfer due to the effective phonon transfer path. The best multilayered composite had the highest in-plane thermal conductivity, which was 471% higher than that of a PEEK. This study provides information about the filler size and stacking patterns for more effective multilayer structures with polymer and filler layers to achieve high performance on mechanical and thermal properties.

Rational Regulation of Optimal Oxygen Vacancy Concentrations on VO2 for Superior Aqueous Zinc-Ion Battery Cathodes.

VO2 with its special tunnel structure and high theoretical capacity is an ideal candidate for cathode materials for aqueous zinc-ion batteries (ZIBs). However, the slow kinetics and structural instability due to the strong electrostatic interactions between the host structure of VO2 and Zn2+ hinder its application. Defect engineering is a well-recognized strategy for improving the intrinsic ion-electron dynamics and structural stability of this material. However, the preparation of oxygen vacancies poses significant difficulties, and it is challenging to control their concentration effectively. Excessive or insufficient vacancy concentration can have a negative effect on the cathode material. Herein, we propose electrode materials with controlled oxygen vacancies prepared in situ on carbon nanofibers (CNF) by a simple, one-step hydrothermal process (Ov-VO2@CNF). This method can balance the adsorption energy and migration energy barrier easily, and we maximized the adsorption energy of Zn2+ while minimizing the adsorption energy barrier. Notably, the Ov2-VO2@CNF electrode delivered a high specific capacity (over 450 mAh g-1 at 0.1 A g-1) and excellent cycle stability (318 mAh g-1 at 5 A g-1 capacity after 2000 cycles with a capacity retention of 85%). This rational design of precisely regulated defect engineering provides a way to obtain advanced electrode materials with excellent comprehensive properties.

Nanodroplets Engineered with Folate Carbon Dots for Enhanced Cancer Cell Uptake toward Theranostic Application.

The research in nanotherapeutics is rapidly advancing, particularly in the realm of nanoconstructs for drug delivery. This study introduces folate-based carbon dot-decorated nanodroplets (f-Dnm), synthesized from a binary mixture of negatively charged folic acid carbon dots (f-CDs) and cationic-branched polyethylenimine (PEI). The uniformly spherical nanodroplets with an average diameter of 115 ± 15 nm exhibit notable photoluminescence. Surface potential analysis reveals a significant change upon coacervation, attributed to strong electrostatic interactions between f-CD and PEI. The engineered nanodroplets show excellent colloidal and photostability even after 6 months of storage at room temperature. The pH-dependent self-assembly and disassembly properties of f-Dnm are explored for drug loading and release studies using doxorubicin (DOX) as a model anticancer drug. Moreover, the f-Dnm nanocarrier demonstrates significantly higher drug loading capabilities (∼90%). In vitro release studies of doxorubicin-loaded f-Dnm [f-Dnm(DOX)] reveal 5 times higher drug release at lysosomal pH 5.4 compared to that at physiological blood pH 7.4. Cytocompatibility assessments using the MTT assay on HeLa, A549, and NIH-3T3 cells confirm the nontoxic nature of f-Dnm, even at high concentrations. Additionally, f-Dnm(DOX) exhibits higher cytotoxicity in HeLa cells compared to f-CD(DOX) at similar DOX concentrations. Cellular uptake studies show an increased uptake of f-Dnm in folate receptor-positive HeLa and MDA-MB 231 cells. Hemolysis assay validated the biocompatibility of the developed formulation. Overall, these engineered nanodroplets represent a class of nontoxic nanocarriers that offer promising potential as nanotherapeutics for folate receptor-positive cells.

Pre-removing partial ammonium ion induces vanadium vacancy assist NH4V4O10 as a high-performance aqueous zinc ion battery cathode

Ammonium vanadate (NH4V4O10) is regarded as a promising cathode material for aqueous zinc-ion batteries, given its considerable theoretical capacity and tunable interlayer spacing. However, due to its inherent low electrical conductivity and the excessive presence of ammonium ions between layers, NH4V4O10 exhibits unsatisfactory electrochemical performance. In this study, it is proposed that the electrochemical performance of NH4V4O10 can be significantly enhanced by removing part of the ammonium cation and increasing the vanadium vacancy. The decrease of ammonium further increases the layer spacing, reduces the irreversible deamination and accelerates the diffusion of Zn2+. Density functional theory (DFT) calculations reveal that increasing vanadium vacancies significantly diminishes the strong electrostatic interactions between the V-O layers and Zn2+, enhances the material’s electrical conductivity, and stabilizes the crystal structure during zinc ion (de)intercalation, thus obtaining excellent electrochemical properties. As a result, the Vd-NVO cathode demonstrates a high reversible capacity of 371 mAh g−1, excellent rate performance, and remarkable cyclic stability, maintaining a reversible capacity of 131 mAh g−1 even after 1000 cycles at 5 A g−1.

Synthesis of strongly interactive FeWO4/BiOCl heterostructures for efficient photoreduction of CO2 and piezo-photodegradation of bisphenol A

Development of multi-functional photocatalysts for CO2 reduction and pollutant elimination is practically significant for solving the environmental problems and energy shortages. In this study, we have immobilized FeWO4 (FWO) nanoparticles on the surface of (001)-facet-exposed BiOCl (BOC) nanosheets through their strong electrostatic interaction to form FWO/BOC heterojunctions. Experimental and theoretical studies corroborate that the FWO/BOC heterojunctions exhibit high-efficiency Z-scheme transfer and separation of photocarriers, and possess excellent photocatalysis for CO2 reduction and bisphenol A (BPA) degradation. Under simulated-sunlight irradiation, the 9 %FWO/BOC heterojunction exhibits a photoreduction performance with CH4/CO yield rates of 4.25/9.41 μmol g−1 h−1 (5 h reaction), which are 3.86/5.26 times higher than those for bare BOC; whereas its photodegradation performance (η(60 min) = 66.8 %, kapp = 0.01755 min−1) is enhanced by 4.3 and 2.7 times compared with that of bare FWO and BOC, respectively. Furthermore, when ultrasonic vibration is simultaneously employed during the simulated-sunlight illumination, the ultrasonic-induced piezoelectric polarization field in BOC nanosheets accelerates the bulk photocarrier separation, resulting in a further improvement in the BPA degradation, and the calculated SF = 1.79 quantifies the degree of enhancement achieved by piezo-photocatalysis collaboration. The introduction of a moderate amount of H2O2 or peroxymonosulfate (PMS) in the reaction solution plays a significant role in promoting the BPA degradation due to the generation of additional •OH and •SO4− reactive species. The mechanisms for photocatalytic CO2 reduction and piezo-photodegradation of BPA catalysis were deeply studied by combining experiments and theory.

High-performance flexible piezoelectric nanogenerator assisted by a three-phase PVDF/WS2/rGO nanocomposite

The emergence of piezoelectric nanogenerators (PENGs) presents a promising alternative to supply energy demands within the realms of portable and miniaturized devices. In this article, the role of 2D transition metal dichalcogenide tungsten sulfide (WS2) and conductive rGO sheets as filler materials inside the polyvinylidene fluoride (PVDF) matrix on piezoelectric performances has been investigated extensively. The strong electrostatic interaction between C–F and C–H monomer bonds of PVDF interacted with the large surface area of the WS2 nanosheets, increasing the electroactive polar phases and resulting in enhanced ferroelectricity in the PVDF/WS2 nanocomposite. Further, the inclusion of rGO sheets in the PVDF/WS2 composite allows mobile charge carriers to move freely through the conductive network provided by the rGO basal planes, which improves the internal polarization of the PVDF/WS2/rGO nanocomposites and increases the electrical performance of the PENGs. The PVDF/WS2/0.3rGO nanocomposite-based PENG exhibits maximum piezoresponses with ∼8.1 times enhancements in the output power density than the bare PVDF-based PENG. The mechanism behind the enhanced piezoresponses in the PVDF/WS2/rGO nanocomposites has been discussed.