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The advancement of gas sensor technology over the past decades has led to remarkable progress and achievements in pollution control and environmental protection. Compared with other sensing materials, electrospun nanofibers have attracted significant attention, which is mainly due to their unique characteristics, including but not limited to high surface area, easy structure design, facile facility setup, multifunctional properties, etc., making them outstanding candidates for potential applications in this field. This review provides an overview of the applications of electrospun nanofibers in gas sensors, concentrating on carbon monoxide, hydrogen, carbon dioxide, hydrogen sulfide, ammonia, nitrogen oxides, oxygen, and volatile organic compounds. It begins with a brief introduction to sensing materials and the advantages of electrospun nanofibers along with their ongoing research. The principles and progress of electrospinning are then discussed. Afterward, the corresponding properties of electrospun nanofibers in diverse gas sensors are thoroughly reviewed. Finally, a future vision regarding challenges and perspectives in this area is proposed. This review provides an extensive and comprehensive reference to utilize advanced electrospun nanofibers to generate novel sensors, facilitating their performance in high-demand areas.

The demand for CO2 detection steadily increases mainly due to the greenhouse effect caused by CO2 emission, which significantly impacts the environment. Among different promising candidates, carbon-based (i.e., graphene, carbon nanotubes, carbon nanoparticles, etc.) composites have been widely studied due to their exceptional mechanical, electrical, and thermal properties. Carbon-based composites also offer high strength-to-weight ratios, excellent conductivity, and superior thermal stability, making them ideal materials for various industrial applications. Despite tremendous efforts to develop CO2 sensors from these materials, obtaining a well-dispersed system that is affordable and easy to use remains challenging. In this work, we have demonstrated a low-cost and effective chemiresistive CO2 sensor based on a composite of functionalized carbon nanotubes (f-CNTs) with polyethyleneimine (PEI). When modified with pyrene and chlorosulfonic acid, the resultant f-CNTs have outstanding dispersibility in PEI, which is mainly attributed to the non-covalent bonds between the CNTs and pyrene and the interaction between the amine and sulfonate groups. The rheology of the f-CNT/PEI composites has been thoroughly studied, which tremendously influences the screen-printing quality. The resulting sensor shows excellent selectivity and sensitivity, which can respond to the CO2 concentration in a wide range of 300 - 5000 ppm. The effects of ink dilution and humidity from the environment on the sensor performance have also been further explored. More importantly, the working mechanism has been proposed, and we hope it can provide insight and a new pathway for future sensor design.

Lithium−halogen exchange of (Z)-1,2-diphenyl-3-(2-iodoethenyl)cyclopropene (1) and subsequent addition to (η4-1,5-cod)PtCl2yields the platinabenzene (η5-C5H3Ph2)[PtC5H3Ph2] (7), in which the metallacyclic ring and C5H3Ph2(Cp′) unit are both derived from the cyclopropene skeleton. Starting instead with (η5-C5Me5)Pt(CO)I, treatment with three nucleophilic (Z)-3-(2-lithiovinyl)cyclopropenes provides platinabenzenes (η5-C5Me5)[PtC5H3PhR] (R = Ph (8), t-Bu (9), Me (10)) in low to modest yield. All platinabenzenes have been fully characterized by NMR spectroscopy and X-ray crystallography. Intermediate σ-vinyl complexes (η5-C5Me5)Pt(σ-C5H3PhR) (R = Ph (14), t-Bu (15)) are also isolated from the reaction mixtures and convert cleanly to the corresponding platinabenzenes in near quantitative yield. Reactivity studies of (η5-C5Me5)[PtC5H3Ph2] with a variety of reagents/conditions are also reported. [ABSTRACT FROM AUTHOR]