Electrospun Polyacrylonitrile Nanofibers Research Articles

Effect of stabilization and carbonization treatment on the chemical and physical transformation of polyacrylonitrile (PAN) based electrospun carbon nanofibers

The present study delves into the production of carbon nanofibers (CNFs) utilising electrospun polyacrylonitrile (PAN) nanofiber mats, with a specific focus on the influence of oxidative stabilisation and carbonisation treatments. This research aims to thoroughly understand how variations in stabilisation time and temperature, as well as carbonisation temperature, impact the CNFs properties. These properties include fiber size, morphology, chemical and crystal structure transformation, thermal behaviour, and surface characteristics. Our methodology involved a detailed examination of the thermal treatment processes, where we observed a significant decrease in fiber size, though the surface morphology of the fibers remained largely unaffected. We employed Fourier-transform infrared (FTIR) spectroscopy to track the transformation of nitrile groups in PAN to imine groups, which indicated the progression of cyclisation reactions. Complementary analyses through differential scanning calorimetry (DSC) confirmed a high degree of these reactions, particularly at stabilisation temperatures extending to 250 °C and beyond. The cyclisation process was found to be complete during the carbonisation phase, at temperatures reaching 450 °C and above. Further, x-ray diffraction (XRD) patterns offered insight into the changes in the crystal structure, particularly in the packing of the d(002) spacing because of the stabilisation and carbonisation processes. This findings from this study not only elucidate the intricate process of CNFs production from electrospun PAN nanofiber mats but also highlight the critical factors that influence their final properties. These insights are invaluable for the development of advanced CNFs with tailored properties suitable for a range of applications, including but not limited to energy storage, electronics, and as supporting materials in various technological domains.

Synergistic effect of pore generation and nitrogen doping on the enhanced CO2 capture and selectivity of carbon nanofibers

The porosity and heteroatom doping of carbon materials are crucial for their adsorption capacity and selectivity toward CO2. Herein, nitrogen-doped microporous carbon nanofibers (CNFs) were prepared by carbonizing electrospun polyacrylonitrile (PAN) nanofibers, using nitrogen-rich polyvinylpyrrolidone (PVP) as porogen and nitrogen source simultaneously. The synergistic effect of pore generation and nitrogen doping improved the porosity and preserved a substantial nitrogen content in the CNFs. Compared to the nitrogen-free polyethylene glycol (PEG) porogen, the incorporation of PVP can facilitate nitrogen doping during the carbonization process. With an increasing amount of PVP addition, the specific surface area of the CNFs significantly expanded to 410 m2/g, maintaining a high nitrogen content of 10.32 wt%. The porosity and nitrogen functionalities (Pyridinic N and pyrrolic N) collaborated synergistically in determining CO2 adsorption capacity, with elevated nitrogen content resulted in improved selectivity. The CNFs exhibited remarkable IAST CO2/N2 (10:90) selectivity of 38 and cycling stability, demonstrating their potential for long-term practical applications. This work provides unique inspiration for the design of porous nanofibers with exceptional CO2 adsorption capacity and selectivity.

In situ synthesis of three-dimensional electrospun polyacrylonitrile nanofiber network reinforced silica aerogel for high-efficiency oil/water separation

In situ synthesis of three-dimensional electrospun polyacrylonitrile nanofiber network reinforced silica aerogel for high-efficiency oil/water separation

Evaporation-Driven Energy Generation Using an Electrospun Polyacrylonitrile Nanofiber Mat with Different Support Substrates.

Water evaporation-driven energy harvesting is an emerging mechanism for contributing to green energy production with low cost. Herein, we developed polyacrylonitrile (PAN) nanofiber-based evaporation-driven electricity generators (PEEGs) to confirm the feasibility of utilizing electrospun PAN nanofiber mats in an evaporation-driven energy harvesting system. However, PAN nanofiber mats require a support substrate to enhance its durability and stability when it is applied to an evaporation-driven energy generator, which could have additional effects on generation performance. Accordingly, various support substrates, including fiberglass, copper, stainless mesh, and fabric screen, were applied to PEEGs and examined to understand their potential impacts on electrical generation outputs. As a result, the PAN nanofiber mats were successfully converted to a hydrophilic material for an evaporation-driven generator by dip-coating them in nanocarbon black (NCB) solution. Furthermore, specific electrokinetic performance trends were investigated and the peak electricity outputs of Voc were recorded to be 150.8, 6.5, 2.4, and 215.9 mV, and Isc outputs were recorded to be 143.8, 60.5, 103.8, and 121.4 μA, from PEEGs with fiberglass, copper, stainless mesh, and fabric screen substrates, respectively. Therefore, the implications of this study would provide further perspectives on the developing evaporation-induced electricity devices based on nanofiber materials.

Nanofibrous Covalent Organic Frameworks Based Hierarchical Porous Separators for Fast‐Charging and Thermally Stable Lithium Metal Batteries

AbstractEngineering multifunctional smart separators are important for the ongoing pursuit of fast‐charging and safe batteries. Herein, a novel nanofibrous covalent organic framework (COF) based separator with well‐designed hierarchical porous channels is fabricated to effectively regulate mass transport for fast‐charging and thermally stable lithium metal batteries (LMBs). Such a hierarchical porous separator consists of electrospun polyacrylonitrile nanofibers with macroporous channels (average diameter of 323 nm) and mesoporous channels (≈7 nm) created between amide‐group‐bonded COF nanoparticles with intrinsic 1.6 nm lithiophilic microporous channels (PAN/AM‐COF). Computational fluid dynamics and density functional theory calculations demonstrate that PAN/AM‐COF can simultaneously facilitate high‐speed and selective transport of Li+, as well as homogeneous deposition of Li, achieving high conductivity (3.33 mS cm−1) and high Li+ transference number (0.79). As a result, Li || LFP full cell with PAN/AM‐COF displays superior cycling stability at 10 C with an acceptable capacity attenuation (0.037% per cycle) over 1000 cycles. Moreover, when operating under an extreme temperature of 100 °C, the Li || LFP full cell with PAN/AM‐COF can still operate stably for 300 cycles at 30 C, highlighting its potential processing scalability for ultrafast‐charging energy storage systems. This study gives insights into designing functional separators for fast‐charging LMBs.

Hierarchical porous N-doped carbon fibers enable ultrafast electron and ion transport for Zn-ion storage at high mass loadings

Zinc-ion capacitors (ZICs) are a promising and safe energy storage system for portable electronics but usually limited by relatively low areal capacity and energy density. Although increasing the mass loading has been suggested, thick electrode layers and clogged pores unavoidably lead to sluggish electron transport and ion diffusion as well as “dead volume” of active materials. Herein, a millimeter-scale 3D thick-network electrode, composed of closely intertwined hierarchical porous N-doped and free-standing carbon nanofibers (HPNCFs), was fabricated via carbonization of nanoscale zeolitic imidazolate framework (ZIF-8) particles embedded in electrospun polyacrylonitrile (PAN) nanofibers. With fast electron/ion transport, large ion-accessible surface area and high utilization rate of active materials, the mass loading of the HPNCFs electrode can reach 48.67 mg cm−2 with a thickness of 4.46 mm. Moreover, the HPNCFs-based ZICs can yield a superior areal/gravimetric capacity of 4.13 F cm−2 /280 F g−1, superior rate capability up to 193.7 F g−1 even at 100 A g−1, high energy density of 99.6 Wh kg−1, and long-term stability for 40,000 cycles. The straightforward approach can provide an opportunity to prepare efficient thick electrodes that could be applied in electrocatalysis, energy storage/conversion, and other electrochemical energy-related techniques.

Highly conductive and transparent metal microfiber networks as front electrodes of flexible thin-film photovoltaics

Simultaneously enhancing the optical transmittance and electrical conductivity of transparent conductors (TCs) applicable in various optoelectronic devices is a long-standing challenge. Herein, we present an innovative approach for fabricating electroplated Ni and Cu microfiber networks (NiMF and CuMF) as highly conductive TCs to realize high efficiency and desired aesthetics in thin-film solar cells and modules. The metal microfibers (MFs) are fabricated using electrospun polyacrylonitrile nanofibers as the template. The large cross-sectional aspect ratio of the metal MF networks remarkably and concurrently improves their electrical conductivity and optical transmittance. Between the NiMF and CuMF TCs, the CuMF sample exhibits a superior figure of merit owing to its exceptionally low electrical resistivity. The metal MF TC is a promising alternative to conventional patterned grids used in flexible Cu(In,Ga)Se2 thin-film solar cells, because it effectively reduces the series resistance, which is advantageous for large-area cells. The CuMF can be successfully employed as a ribbon to maintain the solar cell performance in centimeter-scale cells connected in series. The outstanding performance of the metal MF TCs indicates their potential to eliminate complicated monolithic integration processes or front grids and ribbons in flexible thin-film solar cells and modules.

Modification of electrospun polyacrylonitrile nanofiber membranes with curcumin quantum dots for enhanced self-cleaning, antifouling and photocatalytic performance for water treatment

This work presents the fabrication of electrospun PAN-CMQD nanofiber membranes by blending laser ablated curcumin quantum dots (CMQD) with polyacrylonitrile (PAN) for water treatment application. The electrospinning process conditions were optimized using TOPSIS-Taguchi L9 (33) approach to develop membranes with superior membrane performance. The PAN-CMQD nanofiber membranes were of average fibre diameter 85.89 nm and exhibited increased hydrophilicity and improved membrane performance with 53.01 %, 36.74 %, 58.03 %, 37.68 % and 57.33 % increase in porosity, solute rejection, fouling rejection ratio, tensile strength and pure water flux respectively in contrast to the pristine PAN membrane. The PAN-CMQD nanofiber membrane possessed enhanced recyclability, self-cleaning ability, antibacterial activity and also showed good heavy metal ion removal efficiency towards Pb2+, Fe2+, Cr6+, Cd2+ and Mn2+. The PAN-CMQD membrane also showed 98.80 % photocatalytic degradation efficiency towards methylene blue dye under visible light irradiation. This study proves that PAN-CMQD nanofiber membrane is efficient in treating contaminated water with improved photocatalytic and self-regeneration capacity and the developed membrane could possibly be deployed for the mitigation of heavy metals and dyes from industrial waste water.

Preparation and Support Effect of Graphdiyne Nanotubes with Abundant Cu Quantum Dots.

Graphdiyne (GDY) is considered a very attractive support for metal nanocatalysts due to its unique structure and superior properties. The metal-GDY interaction can significantly affect the performance of catalysts. Herein, GDY nanotubes abundant in in situ formed Cu quantum dots (QDs) (Cu-GDYNT) are prepared using the electrospun polyacrylonitrile nanofibers collected on the surface of electrolytic Cu foil as templates. The diameter of the Cu-GDYNT is controllable and the uniform size of the embedded Cu QDs is about 2.2 nm. And then, the uniformly dispersed and highly active supported catalysts of ruthenium nanoparticles (Rux/Cu-GDYNT) are produced using the Cu-GDYNT as the support. Among them, the Ru3/Cu-GDYNT exhibit outstanding HER performance at all pH levels. Only 17, 67 and 83 mV overpotential is required to reach a current density of 10 mA cm-2 in 1.0 M KOH, 0.5 M H2SO4 and 1.0 M neutral PBS solutions, respectively. The sample exhibits 3000 CV cycle stability and 20 h continuous electrolysis without performance degradation in an alkaline medium. This work provides a new idea for constructing the GDY-supported metal nanocatalysts.

A Finite Element Method for Determining the Mechanical Properties of Electrospun Nanofibrous Mats.

This study focuses on the mechanical properties of electrospun nanofibrous mats, highlighting the importance of the characteristics of single nanofibers in determining the overall mechanical behavior of the mats. Recognizing the significant impacts of the diameter and structural properties of the nanofibers, this research introduces a novel methodology for deriving the effects of the mechanical properties of single nanofibers on the aggregate mechanical performance of electrospun oriented nanofiber mats. For this purpose, a finite element method (FEM) model is developed to simulate the elastoplastic response of the mats, incorporating the influence of structural parameters on mechanical properties. The validation of the FEM model against experimental data from electrospun polyacrylonitrile (PAN) nanofibers with different orientations demonstrates its effectiveness in capturing the elastic-plastic tensile behaviors of the material and confirms its accuracy in terms of reflecting the complex mechanical interactions within the nanofibrous mats. Through a detailed analysis of how nanofiber diameter, orientation of fibers, length-to-width ratio, and porosity affect the mechanical properties of the mats, this research provides valuable insights for the engineering of nanofibrous materials to meet specific mechanical requirements. These findings improve our understanding of nanofibrous mat structures, allowing for better performance in diverse applications as well as highlighting the critical importance of identifying the properties of single nanofibers and their associated impacts on material design.

In situ growth of ZIF-8 on nanofibrous membrane for long-term ultra-high flux coalescence separation of oil-in-water emulsion

The presence of oil-in-water (O/W) emulsions poses a serious threat to the equilibrium of aquatic ecosystems, contaminates potable water resources, and disrupts the structure of soil layers. Consequently, there is an urgent need for effective and economically viable methods for removing emulsified oil droplets from water. The coalescence method has been proposed as an effective means of separating O/W emulsions. In this study, we developed an in situ growth strategy to decorate zeolitic imidazolate framework-8 (ZIF-8) on electrospun polyacrylonitrile (PAN) nanofibers for coalescence separation. The in situ growth process commenced with pretreatment to activate the PAN membrane, creating anchor sites for zinc ions, which was followed by immersion in precursors of ZIF-8 particles. The incorporation of ZIF-8 enhanced amphiphilicity, and roughness, and imparted a positive charge to the membrane, which was anticipated to effectively demulsify and coalesce oil droplets with a negative charge. The ZIF-8/PAN nanofiber membrane obtained a separation ratio exceeding 99.9 % for surfactant-free emulsions and 97.1 % for surfactant-stabilized emulsions. It also demonstrated an ultra-high permeation flux of 21,177 L m−2 h−1 and 14,118 L m−2 h−1, respectively, in a long-term continuous separation process.

Channel engineering strategy of precisely modified MOF/nanofiber composite separator for advanced aqueous zinc ion batteries

As the combination of metal-organic framework (MOF) materials with adjustable channels and flexible polymeric matrix, MOF/nanofiber composite separators enable the controllable ion transport behavior, which offers promising candidates for developing novel battery separators. In this study, series MOF functionalized electrospun polyacrylonitrile nanofiber separators were successfully developed via a precisely surface grafting strategy and then served as the separators for highly efficient aqueous zinc (Zn)-ion batteries (ZIBs). Moreover, channel engineering was developed by placing amino (MOF-N) and sulfonic acid groups (MOF-NS) on the channel surface of UIO-66, which then effectively promoted the ion transport progress. In particular, the resultant MOF-NS shows an excellent ionic conductivity (22.81 mS cm−1), improved Zn2+ transference number (0.78), and outstanding cyclic durability. These enhanced properties can be contributed by the effectively promoted dissociation of zinc salts and desolvation processes of hydrated Zn ions through strong ion-dipole interactions, as confirmed by the theoretical simulations. Our work demonstrates the great importance of channel engineering in modifying porous MOFs materials and the strong power of the precisely modified MOF/nanofiber separators in regulating ion transmission behavior and thus offers a promising separator candidate for high performance aqueous ZIBs.

Targeted elimination of molybdenum ions from a leaching solution with the ability of radiated grafting GMA-PAN nanofibers

In this study, electrospun polyacrylonitrile nanofibers were effectively functionalized for enhanced molybdenum ion adsorption through a multi-step approach. Initially, glycidyl methacrylate was grafted onto the nanofibers via irradiation-induced grafting polymerization, followed by chemical modification with various amino groups, with triethylamine identified as the optimal modifier. The impacts of key synthesis parameters and reaction conditions on grafting level and adsorption capacity were thoroughly investigated, with a focus on achieving maximum efficiency. The resulting nanofibers were characterized using FTIR, SEM, and BET techniques, confirming the successful modification and structural features conducive to adsorption. Furthermore, a comprehensive experimental design, incorporating a central composite design, yielded optimal conditions for molybdenum adsorption, with key parameters including monomer concentration, irradiation dose, adsorbent mass, initial concentration, time, pH, temperature, and amine concentration. The adsorption kinetics were effectively described by the pseudo-second-order model, while the Langmuir isotherm model provided valuable insight into the adsorption behavior. Impressively, the adsorbent exhibited exceptional adsorption efficiency, surpassing 98% even after six adsorption–desorption cycles using 0.5 M HCl. Thermodynamic analysis revealed the exothermic nature of the adsorption process, along with decreased entropy and overall spontaneity, underlining the favorable conditions for molybdenum adsorption. Notably, the synthesized adsorbent demonstrated notable selectivity for molybdenum and achieved an impressive adsorption capacity of 109.79 mg/g, highlighting its potential for practical applications in molybdenum removal from aqueous solutions.

Investigation of Electrospun Polyacrylonitrile and Cellulose Acetate Smart Nanofibers Doped with Expanded Graphite for the Structure and Photothermal Effect

In this study, photothermal effect by doping expanded graphite (EG) to smart nanofibers produced by electrospinning method was investigated. Fourier transform infrared (FT-IR) spectroscopy was exploited for chemical characterization. Thermal analysis experiments were carried out by heating and cooling curves. Surface morphology of the produced materials was investigated through scanning electron microscope (SEM). Contact angle was determined through contact angle measurement device. The appearance of the peak of the characteristic cyano group in the structure of Polyacrylonitrile (PAN) at 2237.02 cm-1 in the nanofibers having different percentages synthesized with EG and PAN was accepted as the evidence of PAN nanofibers formation. The temperature platforms in the heating/cooling curves exhibited that the temperature of the PAN and cellulose acetate (CA) nanofibers mixed with different EG percentage have higher than pristine nanofibers. The surfaces of the EG@PAN and EG@CA nanofibers were homogeneously distributed fibrous, excessive EG heterogeneously dispersed or electrosprayed in shape. The maximum contacts angles were measured as 67.96° and 52.88° for nanofibers synthesized with EG@CA and EG@PAN, respectively. As the result, the temperature of the nanofibers mixed EG at different percentages increased resulting from having the higher thermal conductivity of EG. Main goal of the study is both investigating photothermal effect in PAN and CA electrospun nanofibers doped with EG of activating heat accumulation property of the produced smart nanofibers for heat energy production from the solar. Thus, it will be possible to develop a new promising method in the production of the smart textile products that have the storage capacity of the solar energy.

Catalytic activity of Co (II)-porphyrin anchored onto polymeric support of electrospun polyacrylonitrile nanofiber: synthesis and efficient green oxidation of crystal violet dye with hydrogen peroxide

AbstractA novel method was explored in this study to address water contamination challenges by utilizing nanofiber mat-supported metalloporphyrin materials. Specifically, electrospinning was employed to create various compositions of polyacrylonitrile (PAN) mixed with different concentrations of Co(II) complex of tetrakis-5, 10, 15, 20 (4-hydroxyphenyl)porphyrin Co(II)TPHPP 1 anchored to chloroacetylated poly (p-hydroxy styrene) CAPS. These resulting nanofiber mat-supported metalloporphyrin materials were comprehensively analyzed using UV, FTIR spectrum, SEM, and TGA thermographs. The study found that the designed nanofibers acted as efficient catalysts for the oxidative breakdown of crystal violet (CV) dye using H2O2 in aqueous solutions. Among these materials, the nanofiber composed of a 1:1 ratio of PAN to Co(II)TPHPP/CAPS with a lower Co(II)TPHPP loading (NF6), demonstrated the highest catalytic activity, decomposing CV completely within 60 min. Various experiments were conducted to explore the effects of H2O2 concentration, catalyst dosage, and temperature on the catalytic degradation of CV with the NF6 nanofiber mat-supported metalloporphyrin. An interesting finding was the enhanced recovery and recyclability of the catalyst due to the immobilization of metalloporphyrin on chloroacetylated polymer-supported nanofiber mats. Remarkably, even after five cycles of reuse, there was no significant degradation in the catalytic activity of the recycled catalyst. This breakthrough highlights the potential of these materials in addressing water pollution challenges efficiently and sustainably.

Green synthesis of ZnO nanoparticles decorating electrospun PAN nanofibers for enhanced radiation shielding

A comprehensive examination was conducted in our study regarding the incorporation of zinc oxide (ZnO) nanoparticles into polyacrylonitrile (PAN) nanofibers to improve their radiation protection properties. Using the electrospinning technique, ZnO nanoparticles that were synthesized via the environmentally benign ascorbic acid method were subsequently applied to PAN nanofibers. A multitude of coefficients, including the natural attenuation coefficient and mass attenuation coefficient, are pivotal in evaluating the efficacy of composite materials with regard to radiation protection. It was subjected to a comprehensive evaluation that considered a number of crucial factors: The incorporation of ZnO nanoparticles into PAN nanofiber composites leads to a substantial augmentation in the mass attenuation coefficient, which surges from 0.185 cm2/g to 0.221 cm2/g when compared to pure PAN nanofibers. Similarly, the coefficient of linear attenuation rises from 0.284 1/cm to 0.320 1/cm.

Modification of PAN electrospun nanofiber membranes with g-C3N4 nanotubes/carbon dots to enhance MBR performance

This study is dedicated to the enhancement of electrospun polyacrylonitrile (PAN) nanofiber membranes for their application in membrane bioreactor (MBR) processes. The improvement is achieved through the incorporation of graphitic carbon nitride nanotubes/carbon dots (g-C3N4 NT/CDs) and subsequent heat post-treatments at varying temperatures. Notably, the hot-pressing methodology effectively mitigates surface roughness and significantly reduces issues related to peeling during nanofiber experimentation. Our results demonstrate that the introduction of 0.5 wt% of g-C3N4 NT/CDs leads to a substantial enhancement in water flux. In particular, nanocomposite membranes subjected to hot-pressing at 90 °C for 10 min exhibited an impressive flux recovery ratio (FRR) of 70%. Furthermore, the heat-treated nanocomposite membranes exhibited remarkable antifouling properties and significantly reduced fouling rates when compared to their heat-treated bare counterparts. This study underscores the noteworthy potential of g-C3N4 NT/CDs-modified PAN nanofiber membranes to substantially elevate MBR performance, firmly positioning them as highly promising candidates for critical applications in the domains of water and wastewater treatment. However, it is imperative to underscore that the existing written material necessitates a comprehensive overhaul to align with the provided structural framework.

Structural energy storage system using electrospun carbon nanofibers with carbon nanotubes

AbstractIn the present study, carbon nanofibers containing multi‐walled carbon nanotubes (MWCNTs) were fabricated and employed as electrodes for structural supercapacitors. Carbon nanofibers were utilized as the electrode material in structural supercapacitors to increase the specific surface area. Electrospun polyacrylonitrile (PAN) nanofibers underwent conversion to carbon nanofibers through stabilization and carbonization processes aided by thermal treatment. The specific surface area of the electrospun carbon nanofiber electrodes was further increased approximately 118 times (1946.9 m2/g) using an activation process in comparison with that of non‐activated carbon nanofibers (16.43 m2/g). Multifunctional supercapacitors were fabricated by employing electrospun carbon nanofibers and a vacuum resin infusion technique. The specific capacitance of activated carbon nanofibers (ACNF) and ACNF‐MWCNT exhibited significant improvement (14.87 and 48.25 mF/cm2, respectively) compared to non‐activated carbon nanofibers (CNF‐MWCNT: 1.71 mF/cm2). This improvement was attributed to the reduction in equivalent series resistance and the increase of the surface area of the nanofiber electrodes. Additionally, the carbon nanofiber electrodes contributed to an increased interlaminar fracture toughness of structural supercapacitors, acting akin to “Velcro” between fabric interfaces. This work serves as a “proof of concept” for a straightforward and efficient method to manufacture electrodes for structural supercapacitors based on the electrospinning technique.Highlights Fabrication of carbon nanofibers containing MWCNTs using electrospinning. The carbon nanofiber as an electrode for structural supercapacitors. Simple and effective method. Dramatically improving specific capacitance of the supercapacitors.

Nanofibrous PAN-PDMS Films-Based High-Performance Triboelectric Artificial Whisker for Self-Powered Obstacle Detection.

Avoiding collisions is a key necessity for any autonomous mobile robot, and obstacle mapping enables them to maneuver in an uncharted area. In this era of the Internet of Things, with the emerging need for a multitude of sensors, adopting self-powered technologies is more practically viable than batteries for powering the same. Herein, with the fabrication of a triboelectric artificial whisker (TAW), a self-powered obstacle detection is demonstrated via tactile perception. The mechanical contact with the obstacle gives rise to an electrical signal from the TAW owing to the embedded triboelectric sensor. In addition, the triboelectric nanogenerator (TENG) based on electrospun polyacrylonitrile (PAN) nanofibers and polydimethylsiloxane film, which facilitates this self-powered artificial sensation, generates an output voltage of 720V and current density of 5mA m-2 with 1.7W m-2 of maximum power delivery from a force of 10 N. The electro-spinning aided enhancement in contact area of the PAN is responsible for the remarkable improvement in the performance of the TENG, 3.4 times enhancement in power density, when compared to the nonsurface-modified ones. In addition, the TENG is able to charge commercial capacitors up to appreciable values and demonstrates powering different electronic gadgets such as calculators and thermometers.

High Roughness Induced Pearl Necklace‐Like ZIF‐67@PAN Fiber‐Based Triboelectric Nanogenerators for Mechanical Energy Harvesting

AbstractTechnological developments and innovations in the wearable device field have created huge consumer demand. Hence, designing energy harvesting devices are of utmost importance. Of the various types of energy harvesting devices, triboelectric nanogenerators (TENGs) have come to the fore, as it can efficiently harvest electrical energy from mechanical motions. To date, polymers and metals have dominated the triboelectric series, but there is a need to develop novel composite materials and 2D materials to enhance the performance of TENGs. In this study, electrospun polyacrylonitrile nanofibers are prepared and decorated with zeolitic imidazole framework‐67 (ZIF‐67@PAN) to form pearl‐necklace‐like fibers. ZIF‐67@PAN nanofibers are prepared by immersing PAN nanofibers for different hours (1, 5, 10, and 24 h) in ZIF‐67 solution, they provide more roughness, and efficient surface contact area. The immersion of PAN fibers in ZIF solution for longer times increases overall energy harvesting efficiency. Different amounts of MXene are deposited on PVDF; the inclusion of MXene improves the charge transfer properties of TENGs. PAN@ZIF‐67 is used as a positive tribolayer and PVDF@MXene as a negative tribolayer. The optimized TENG device has 305 V, 10.6 µA, and 10.9 W/m2 power and demonstrated promising energy harvesting characteristics and self‐powered sensing efficiency.