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[Display omitted] • Bimetallic MOFs-derived hierarchical WO 3 /ZnWO 4 /CoWO 4 heterostructures are gained. • Morphology and sensing behavior of the samples are tuned by the amounts of ZIFs. • Good selectivity and stability of WO 3 -based composites can be observed at 25 °C. • Abundant polyoxometalate electron acceptors are distributed on the coarse surface. • Sensing mechanism is relied on the rapid transport of carriers and plentiful POMs. Bimetallic MOFs-derived hierarchical WO 3 /ZnWO 4 /CoWO 4 heterostructures were prepared by electrospinning for achieving superior n-butanol-sensing property at low operating temperatures. Porous chain-like structures can gradually transformed into porous mulberry-like structures composed of various accumulated particles as increasing the additive amount of Zn/Co-ZIFs. High selectivity and stability of WO 3 -based composites to 100 ppm n-butanol can be observed at 25 °C, including the large sensitivity of 32 and the fast response/recovery times of 115/179 s. The enhanced gas-sensing performance is primarily ascribed to the increased specific surface area, plentiful polyoxometalate, and effective heterojunctions, obviously promoting surface/interface absorption behavior and electron transport process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low temperature TEA-sensing SnS 2 /MnS microflowers are originally fabricated. • DFT simulation shows the transformation from semiconductive to metallic nature. • SnS 2 /MnS-3 % exhibits high responses of 17.85/23.67 to 100 ppm TEA at 30/40 ℃. • The enhanced metallicity plays a vital role of the enhanced gas-sensing behavior. • New strategy for gaining effective sulfide RT gas-sensing materials is presented. The development of low-temperature SnS 2 -based sensitive elements with unique surface adsorption and transport regulation for triethylamine (TEA) has always been an intractable challenge. In the present work, ultrathin SnS 2 /MnS microflowers with enhanced metallicity have been prepared by a facile one-step hydrothermal method, which is especially beneficial for achieving superior TEA-sensing performance under room temperature (RT) condition. Compared with pure SnS 2 , the SnS 2 /MnS-3 % can obviously exhibit higher responses of 17.85 and 23.67, faster response/recovery times of 165/506 and 156/344 s, and the enhanced gas selectivity and stability to 100 ppm TEA at 30 and 40 ℃, respectively. Taking account of density functional theory (DFT) calculation, the transformation of SnS 2 -based sensors from semiconductive to metallic nature plays a critical role of the enhanced gas-sensing behavior with the increased gas molecules absorption and electron transport efficiency, which can provide a new strategy for constructing novel and effective sulfide RT gas-sensing composites. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ growth of porous WO 3 /FeWO 4 hierarchical structure is originally obtained. • The distribution of p-n heterojunctions is dependent on the content of MIL-101. • The optimal operating temperatures to n-butanol can be reduced from 220 to 25 °C. • Efficient heterojunction interfaces gain surface electronic structure modulation. • A strategy of novel room temperature n-butanol-sensing performance is presented. This study originally reports the in-situ construction of porous WO 3 /FeWO 4 ribbon-like hierarchical composites with unique and intense heterojunction interface behavior and the enhanced adsorption and carrier transport capability for effectively detecting n-butanol at room temperature. The introduction of different adding amounts of MIL-101 plays the key role of the morphological evolution of WO 3 -based microstructures with the well-distributed nanoparticles in situ growth on the surface by a facile electrospinning and subsequent calcination process. Compared with pristine WO 3 , a sharp and useful reduction of the optimal operating temperature from 220 to 25 °C can be observed as the Fe component increasing, mainly owing to the inverted p-type gas sensitive response caused by the controllable variable of FeWO 4 phase in the multiple effective WO 3 -FeWO 4 heterojunctions. The optimal WO 3 /FeWO 4 composites can display the highest response of 12.3 and a relatively short response/recovery times of 110/140 s to 100 ppm n-butanol at 25 °C, together with the superior gas selectivity, repeatability, humidity and long-term stability. Density functional theory (DFT) simulation is employed for verifying the significant adsorption interaction and charge transfer between n-butanol molecule and WO 3 /FeWO 4. Regular distribution of WO 3 -FeWO 4 heterojunction interfaces can not only determine the collaborative modulation of electronic structures, but also provide the efficient surface/interface transport mechanism for MIL-101 induced one-dimensional (1D) hierarchical ribbons. Actually, the integrated gas-sensitive components based on WO 3 /FeWO 4 composites exhibit the rapid response characteristic under room temperature condition and provide a friendly strategy of optimizing the practical detection of ppm-level n-butanol for other inorganic heterogeneous sensors. [ABSTRACT FROM AUTHOR]