The fire detection plays a critical role in the maintenance of public security. Previous approaches of early fire warning, based on smoke or temperature response must be set in the proximity of a ...fire. They cannot provide the additional information of fire location or size and are susceptible to complicated situations. It is still a big challenge to make rapid and accurate early fire warning in precombustion because of the lack of reliable alarm signals. Herein, a precursor molecular sensor (PMS) is designed and synthesized that can present the chemical structure transformation to form phthalocyanines (Pcs) and release a color change signal at about 180 °C, learning from the plant chlorophyll metabolism. Further, the PMS is assembled to an early fire warning component (EWC) and an intelligent image recognition algorithm is introduced for unburned fire detection. The EWC generates a colorful alarm within 20 s at 275 °C. Therefore, the facile PMS provides a reliable real‐time monitoring strategy to the early fire warning detection in precombustion.
A bioinspired color changing molecular sensor is designed to achieve early fire detection based on transformation of phthalonitrile to phthalocyanine, learning from the plant chlorophyll metabolism. An intelligent image recognition algorithm is applied and the sensor generates colorful alarm within 20 s at 275 °C. This study provides a reliable real‐time monitoring strategy to the early fire detection in precombustion.
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Construction of multifunctional photoelectrochemical energy devices is of great importance to energy saving. In this study, we have successfully prepared a mesoporous WO3 film on FTO glass via a ...facile dip-coating sol–gel method; the designed mesoporous WO3 film exhibited advantages including high transparency, good adhesion and high porosity. Also, multifunctional integrated energy storage and optical modulation ability are simultaneously achieved by the mesoporous WO3 film. Impressively, the mesoporous WO3 film exhibits a noticeable electrochromic energy storage performance with a large optical modulation up to 75.6% at 633 nm, accompanied by energy storage with a specific capacity of 75.3 mA h g−1. Furthermore, a full electrochromic energy storage window assembled with the mesoporous WO3 anode and PANI nanoparticle cathode is demonstrated with large optical modulation and good long-term stability. Our research provides a new route to realize the coincident utilization of optical-electrochemical energy.
In this work, by using two kinds of viologen ligands three POM‐based Compounds were obtained under hydrothermal conditions, namely AgI(bmypd)0.5(β‐Mo8O26)0.5 (1) (bmypd ⋅ ...2Cl=1,1′‐Biphenyl‐4,4′‐bis(methylene)bis(4,4′‐bipyridyinium)dichloride), AgI2(bypy)4(HSiW12O40)2 ⋅ 14H2O (2) and AgI(bypy)(γ‐Mo8O26)0.5 (3) (bypy⋅Cl=1‐Benzyl‐4,4′‐bipyridyinium chloride). The structures were characterized by Fourier transform infrared spectroscopy (FT–IR), Powder X‐ray diffraction (PXRD), X‐ray photoelectron spectroscopy (XPS) and single crystal X‐ray diffraction. Compounds 1–3 show excellent photochromic ability with fast photoresponse under the irradiation of ultraviolet light with different degrees of color changes. So compounds 1–3 can be used as visible ultraviolet detectors. Compounds 1–3 also possess photoluminescence properties with fast and excellent fluorescence quenching effect. Compounds 1–3 also can be used as inkless and erasable printing materials with suspensions of 1–3 applied to filter paper. Compounds 1–3 can also produce color changes in amine vapor environment, especially in an NH3 atmosphere. Compounds 1–3 can be used as organic amine detectors.
Three polyoxometalate‐viologen Compounds were designed and constructed by using two viologen ligands. Compounds 1–3 show excellent photochromic features with fast photoresponse under irradiation of ultraviolet light with different degrees of color changes. These Compounds exhibit amine detecting and inkless and erasable printing properties, and they can be prepared into a mixed matrix film as a good UV detector.
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Free‐standing CaCO3 materials are an important member in biological systems because of their existence in many natural organisms such as nacre, shell, and crustacean cuticle. However, toughness of ...those artificial mineral films is sacrificed once their inorganic content is up to 90%, thus free‐standing characteristics have seldom been achieved for CaCO3 films, let alone their real applications. Herein a fast and simple method for constructing hydrogel “bridges” for CaCO3 microparticles is presented, developing highly flexible free‐standing CaCO3 films with only 5% organic content. Such integrated films have underwater superoleophobicity and self‐cleaning function, which guarantee their repeated application in oil/water separation. Furthermore, heavy metal ions can be efficiently removed by simple filtration with the films. Because of the self‐similar structure, the films are able to resist mechanical abrasion without losing the anti‐wetting property and separation efficiency. The free‐standing CaCO3 films are put forward for the first time to practical application, demonstrating the strategy can bring a brilliant prospect to artificial biomineral materials.
A highly flexible free‐standing CaCO3 film with multiple functions is fabricated by constructing spider web‐simulated hydrogel bridges to connect fragile CaCO3 microparticles together. Owing to underwater superoleophobicity and their self‐cleaning function, allow to apply such films for the first time in oil/water separation and heavy metal removal. A self‐similar structure of the film guarantees good mechanical abrasion resistance without losing functions.
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Due to spontaneous organization of cellulose nanocrystals (CNCs) into the chiral nematic structure that can selectively reflect circularly polarized light within a visible-light region, fabricating ...stretching deformation-responsive CNC materials is of great interest but is still a big challenge, despite such a function widely observed from existing creatures, like a chameleon, because of the inherent brittleness. Here, a flexible network structure is introduced in CNCs, exerting a bridge effect for the rigid nanomaterials. The as-prepared films display high flexibility with a fracture strain of up to 39%. Notably, stretching-induced structural color changes visible to the naked eye are realized, for the first time, for CNC materials. In addition, the soft materials show humidity- and compression-responsive properties in terms of changing apparent structural colors. Colored marks left by ink-free writing can be shown or hidden by controlling the environmental humidities. This biobased photonic film, acting as a new “smart skin”, is potentially used with multifunctions of chromogenic sensing, encryption, and anti-counterfeit.
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The continuation of human civilization has always been accompanied by symbiosis and confrontation with fire. Particularly, humans can comprehensively recognize fire situations based on various ...sensory receptors in organs (eyes, skin, nose, etc.), further forming a sound fire perception system by in‐the‐brain recording, modeling, and understanding fire behaviors, leading to the most accurate fire treatments. If a sensing perception system can mimic human perceptual behavior and carry out real‐time fire recognition, such an active defense system can achieve real fire safety. Here, inspired by the brain‐centered perception system, an early‐fire perception system enabled by a VO2‐based temperature‐flame‐modulated optical switch, and a machine‐learning‐assistant demodulation algorithm is reported. This approach creates real‐time monitoring composed of early fire warning (1 s for candle flame and 4 s for 130 °C heat flow), fire cause recognition (95.7% accuracy in identification), and evacuation advice provision, advancing the technologies in the perception system that enable future sensors the comprehensive perception capability for fire state.
Inspired by brain‐centered perception processes, a machine‐learning‐assistant early fire perception system is demonstrated that can demodulate multiple fire signals and achieve early warning, fire cause identification, and evacuation advice provides. To the best of authors knowledge, this is the first fire perception system featuring real‐time processing abilities with achieving early warning, fire cause identification, and evacuation advice provides.
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•A novel PIL-based quasi solid electrolyte was prepared via one-step in situ polymerization.•The PIL-QSE offers outstanding flexibility, favorable thermal stability and good ...electrochemical stability.•The PIL-QSE can suppress dendrite formation leading to good battery performance.•The PIL-QSE shows a good application prospect in the fields of flexible devices.
Solid-state battery (SSB) has a new application prospect in the fields of safe energy storage, but the solid electrolyte usually fails to maintain excellent ionic conductivity, good mechanical properties and close interfacial contact with the electrode materials simultaneously. A newly-designed poly(ionic liquid)-based quasi solid electrolyte (PIL-QSE) is prepared via one-step in-situ cross-linked polymerizing 1-vinyl-3-dodecylimidazolium bis(trifluoromethanesulfonyl) imide (VDIM-TFSI), which is filled in poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) porous membrane prepared via phase inversion. The leakage-free PIL-QSE containing a compact cross-linked network structure exhibits optimal performances with outstanding flexibility, favorable thermal stability and improved electrochemical performances including a high room-temperature ionic conductivity of 0.70 mS cm−1, a superior electrochemical window up to 5.0 V as well as a high lithium ion transference of 0.52. Furthermore, the PIL-QSE can suppress dendrite formation leading to a good battery performance. The LiFePO4|PIL-QSE|Li cells can maintain a discharge capacity 140.7 mAh g−1 at 0.05 C with 99.8% coulomb efficiency after 200 cycles and 125.9 mAh g−1 at 0.1 C with 98.9% capacity contention after 100 cycles at 25 °C. Because of the flexibility of PIL-QSE, the pouch-type battery based on PIL-QSE cannot only light the red LED lamp in a normal state, but also in a bended/cut state. Both of the excellent performance and easy fabrication of PIL-QSE make it potentially as one of the most promising electrolyte materials for SSPB.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To exploit polyoxometalate (POM)-based metal-organic complexes (MOCs) with outstanding electro- and photo-chemical performances, two new bis-amide derivative N-donor ligands featuring a 'V'-like ...connector, 4,4'-bis(3-pyridinecarboxamide)phenylmethane (L
) and 4,4'-bis(3-pyridinecarboxamide)phenylketone (L
), were designed and reacted with Anderson-type POMs in the presence of Co(II) ions under solvothermal conditions, which generated four MOCs: Co
(L
)
(AlMo
H
O
)·4H
O (1), Co
(HL
)
(H
O)
(TeMo
O
)·2H
O (2), Co
(HL
)
(H
O)
AlMo
H
O
·5H
O (3), and Co
(HL
)
(H
O)
(TeMo
O
)·2H
O (4). All the complexes showed supramolecular structures
hydrogen bond interaction, which resulted from the 2D layers for 1, the satellite-like structural units for 2 and 4, but the 1D chains for 3. In these structures, the POMs and organic ligands exhibited different coordination modes. Both 2 and 4 showed efficient ampere sensing activities for Cr(VI) with lower limits of detection of 0.029 and 0.038 μM, respectively. Complexes 1 and 2 showed good visible-light catalytic behavior toward the reduction of Cr(VI), which offers more chances for developing electrochemical sensors and photocatalysts for Cr(VI).
Smart design and construction of advanced electrodes are crucial for the development of new electrochemical energy storage systems. In this study, we realized hollow 1T MoS2 arrays grown on carbon ...cloth via a template-free solvothermal method. Hollow MoS2 arrays, with diameters of 400–500 nm, are composed of curved MoS2 nanosheets. This well-designed structure and the introduction of metallic phase MoS2 can improve electrical conductivity, shorten the electron/sodium ion diffusion, and accommodate the large volume changes during cycling. Due to these features, when employed as an anode of sodium ion batteries, the hollow 1T MoS2 array electrode delivers superior sodium ion storage properties, including enhanced cycling stability (576 mA h g−1 after 200 cycles at 200 mA g−1) and high rate capability (276 mA h g−1 at high current density of 2 A g−1). Our study may guide the synthesis of other nanostructured metal sulfide anodes for electrochemical energy applications.
A novel in situ chemical upcycling strategy for plastic waste is proposed by the customized diphenylacetylene monomer with dual photo‐response. That is, diphenylacetylene reactive monomers are in ...situ inserted into the macromolecular chain of polyethylene terephthalate (PET) plastics/fibers through one‐pot transesterification of slight‐depolymerization and re‐polymerization. On the one hand, the diphenylacetylene group absorbs short‐wave high‐energy UV rays and then releases long‐wave low‐energy harmless fluorescence. On the other hand, the UV‐induced photo‐crosslinking reaction among diphenylacetylene groups produces extended π‐conjugated structure, resulting in a red‐shift (due to decreased HOMO–LUMO separation) in the UV absorption band and locked crosslink points between PET chains. Therefore, with increasing UV exposure time, the upcycled PET plastics exhibit reverse enhanced UV resistance and mechanical strength (superior to original performance), instead of serious UV‐photodegradation and damaged performance. This upcycling strategy at oligomer‐scale not only provides a new idea for traditional plastic recycling, but also solves the common problem of gradual degradation of polymer performance during use.
Starting from the oligomer‐scale, this work implements a novel in situ chemical upcycling strategy for PET plastic wastes through tailored diphenylacetylene monomer. Uniquely, the dual photo‐responses of diphenylacetylene enable upcycled PET plastics with reverse enhanced UV‐resistance and strength.
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