Advanced Electrospinning Technology Applied to Polymer-Based Sensors in Energy and Environmental Applications

Abstract

Due to its designable nanostructure and simple and inexpensive preparation process, electrospun nanofibers have important applications in energy collection, wearable sports health detection, environmental pollutant detection, pollutant filtration and degradation, and other fields. In recent years, a series of polymer-based fiber materials have been prepared using this method, and detailed research and discussion have been conducted on the material structure and performance factors. This article summarizes the effects of preparation parameters, environmental factors, a combination of other methods, and surface modification of electrospinning on the properties of composite nanofibers. Meanwhile, the effects of different collection devices and electrospinning preparation parameters on material properties were compared. Subsequently, it summarized the material structure design and specific applications in wearable device power supply, energy collection, environmental pollutant sensing, air quality detection, air pollution particle filtration, and environmental pollutant degradation. We aim to review the latest developments in electrospinning applications to inspire new energy collection, detection, and pollutant treatment equipment, and achieve the commercial promotion of polymer fibers in the fields of energy and environment. Finally, we have identified some unresolved issues in the detection and treatment of environmental issues with electrospun polymer fibers and proposed some suggestions and new ideas for these issues.

Keywords: electrospinning; energy collection; environmental applications; polymer; sensors.

Figure 1

Research statistical data on the theme of “Electrospinning and Energy and Environment” retrieved from the literature on the “Web of Science” platform.

Figure 2

The intrinsic characteristics and influencing factors of electrospun PVDF. (a) The schematic diagram for typical α, β, and γ crystalline phases of PVDF [65]. Copyright 2021, reproduced with permission from MDPI. (b) The influence of voltage on the XRD patterns and crystallinity of electrospun PVDF nanofibers [66]. Copyright 2021, reproduced with permission from MDPI. (c) Schematic diagram of the enhancement mechanism of humidity and voltage polarity on piezoelectric performance [67]. Copyright 2020, reproduced with permission from ACS Publications. (d) TEM images δ–PVDF nanoparticles and the difference between the XRD characteristic spectra of phase δ and phase α [68]. Copyright 2022, reproduced with permission from Elsevier.

Figure 3

Schematic diagram of different electrospinning collection devices for preparing piezoelectric nanofibers with different structures. (a) A classic electrospinning device for preparing P (VDF-TrFE) nanofibers [69]. Copyright 2021, reproduced with permission from RSC. (b) Schematic diagram of the fabrication process for copolymer yarns with a geometric arrangement of piezoelectric nanofabrics [70]. Copyright 2020, reproduced with permission from Wiley. (c) Preparation of core-sheath structure using coaxial electrospinning technology [71]. Copyright 2019, reproduced with permission from John Wiley and Sons. (d) Schematic diagram of the preparation device for conjugated electrospun yarn [72]. Copyright 2023, reproduced with permission from Springer Nature. (e) Schematic diagram of preparing piezoelectric nanofiber sensing mat using wet spinning process [73]. Copyright 2023, reproduced with permission from Elsevier.

Figure 4

Schematic diagram of different assembly methods for piezoelectric pressure sensors. (a) Schematic diagram and actual photo of the assembly structure of a typical piezoelectric pressure sensor [60]. Copyright 2018, reproduced with permission from RSC. (b) Schematic diagram of pressure sensor structures with different sensor layer combinations and their optical and infrared images applied on the skin surface [74]. Copyright 2023, reproduced with permission from Springer. (c) Assembly of ultra-thin piezoelectric nanogenerators with three-dimensional structure by combining electrospinning (i), direct writing (ii), vacuum plating (iii) and 3D structure of ANF-PENG (iv) [75]. Copyright 2023, reproduced with permission from Wiley. (d) A schematic diagram of a self-powered frictional nanogenerator constructed using MXene-coated fabric and PBU fibers deposited on Ag-coated conductive fabric, as well as a physical image of the device [76]. Copyright 2023, reproduced with permission from ACS Publication.

Figure 5

Schematic diagram of the fabrication process for gas sensors with different micro/nanostructures. (a) Porous hollow nanofibers prepared by single needle electrospinning with Kirkendall effect to improve H₂S gas sensing performance [81]. Copyright 2020, reproduced with permission from Elsevier. (b) Core-shell nanofibers and heterojunctions for NO₂ detection, along with corresponding band diagrams [83]. Copyright 2021, reproduced with permission from Elsevier. (c) Porous fiber-in-tube nanocomposites for fast triethylamine detection [85]. Copyright 2022, reproduced with permission from ACS Publication. (d) Parallel design of bi-component heterojunction nanofibers for high-performance ethanol gas sensors by side-by-side electrospinning [87]. Copyright 2022, reproduced with permission from Elsevier. (e) Hydrogen sensors assembled by surface-modified particles on nanofibers [89]. Copyright 2022, reproduced with permission from ACS Publications. (f) Electrospun nanofibers modified nanoflowers for rapid response to hydrogen sulfide gas sensors [90]. Copyright 2023, reproduced with permission from Elsevier.

Figure 6

(a) Schematic diagram of PVA/MXene composite fiber humidity sensor prepared by electrospinning [91]. Copyright 2021, reproduced with permission from Springer. (b) Resistance variation curves of MXene, PVA, and PVA/MXene composite fiber sensors exposed to various relative humidity conditions [91]. Copyright 2021, reproduced with permission from Springer. (c) Schematic diagram of electrospinning preparation process and formation mechanism of double-shelled nanotubes, which includes double-shelled structures formed by metal ions and oxygen diffusion during sintering in air, as well as the morphologies of hollow nanotubes and double-shelled nanotubes [86]. Step I, II, III represented the electrospinning process of the precursor nanofiber composites, the metal ions, and oxygen diffusion process during sintering in air, respectively. Copyright 2022, reproduced with permission from Elsevier. (d) A photo demonstrating the LED state of a humidity sensor assembled using an electrospun anisotropic frictional nanogenerator at different relative humidity levels [92]. Copyright 2022, reproduced with permission from Elsevier. (e) The output voltage of the sensor varies with humidity [92]. Copyright 2022, reproduced with permission from Elsevier.

Figure 7

(a) Schematic diagram of a heavy metal ion sensor prepared from a screen-printed carbon electrode modified with electrospun PEDOT/PVA/AgNPs fibers, a surface metal bismuth alloy formed by stripping, and the detection equipment composed of an electrochemical battery system [93]. Copyright 2022, reproduced with permission from Elsevier. (b) Schematic diagram of the interaction between the active layer surface and ions during the sensing process of Pb ions using polymer fibers prepared by electrospinning [94]. Copyright 2023, reproduced with permission from Wiley. (c) The electrochemical detection mechanism of multistage porous legume-like nanofiber aerogel, the repeatability measurement of a small amount of Cd²⁺ and Pb²⁺, and the anti-interference performance of the sensor in a mixed solution containing 50-time interfering ions [95]. Copyright 2023, reproduced with permission from Elsevier. (d) Schematic diagram of a portable electrospun-InZnO nanofibers electrochemical sensor platform for selective capture of Hg(II) ions and electrochemical impedance spectroscopy of Hg(II) ions [96]. Copyright 2022, reproduced with permission from Elsevier.

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(a) Schematic diagram of crosslinked T-PANa/PVA fibers with excellent filtration performance, water resistance, mechanical properties, and optical image of the composite fiber membrane [97]. Copyright 2023, reproduced with permission from Elsevier. (b) The curved-ribbon electrospun nanofibers with environmentally friendly breathability and high-performance air filtration [98]. Copyright 2022, reproduced with permission from Elsevier. (c) Schematic diagram of double-layer structure composite filter medium [99]. Copyright 2023, reproduced with permission from Elsevier.

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(a) Schematic diagram of the preparation process of perfluorooctanoic acid nanofibers, along with SEM and EDS elemental map images and corresponding diameter distribution [100]. Copyright 2023, reproduced with permission from Wiley. (b) Schematic diagram of the preparation of ZIF-8@ZIF-8/polyacrylonitrile nanofibers [101]. Copyright 2020, reproduced with permission from Elsevier. (c) Preparation and adsorption mechanism of core-shell cellulose acetate biocomposite nanofiber membrane [102]. Copyright 2022, reproduced with permission from Springer. (d) Schematic diagram of SiO₂ MgO mixed fibers prepared by solution electrospinning process [103]. Copyright 2020, reproduced with permission from Elsevier.

Figure 10

Schematic diagram of electrospinning material design for dye/organic pollutant removal, the classic catalytic mechanism of composite materials, and application of catalytic degradation in environmental protection. (a) Typical 0D/1D composite nanofiber membrane photocatalysts utilizing electrospinning method [104]. Copyright 2023, reproduced with permission from Elsevier. (b) Schematic diagram of the composition of multi-layer photocatalytic films [107]. Copyright 2023, reproduced with permission from Elsevier. (c) Schematic diagram of a photocatalytic mechanism for degradation of the polymer and two-dimensional composite electrospun films [108]. Copyright 2023, reproduced with permission from MDPI. (d) Application of green photocatalytic materials in the treatment of industrial wastewater pollution and environmental protection [109]. Copyright 2023, reproduced with permission from Elsevier.