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Metal-organic framework (MOF)-polymer mixed-matrix membranes (MMMs) have shown great potential and superior performance in gas separations. However, their sensing application has not been fully established yet. Herein, a rare example of using flexible MOF-based MMMs as a fluorescent turn-on sensor for the detection of hydrogen sulfide (H S) is reported. These MOF-based MMMs are readily prepared by mixing a highly stable aluminum-based nano-MOF (Al-MIL-53-NO ) into poly(vinylidene fluoride) with high loadings up to 70%. Unlike the intrinsic fragility and poor processability of pure-MOF membranes, these MMMs exhibit desirable flexibility and processability that are more suitable for practical sensing applications. The uniform distribution of Al-MIL-53-NO particles combined with the permanent pores of MOFs enable these MMMs to show good water permeation flux and consequently have a full contact between the analyte and MOFs. The developed MMM sensor (70% MOF loading) thus shows a highly remarkable detection selectivity and sensitivity for H S with an exceptionally low detection limit around 92.31 × 10 m, three orders of magnitude lower than the reported powder-form MOFs. This work demonstrates that it is feasible to develop flexible luminescent MOF-based MMMs as a novel platform for chemical sensing applications.

Bi 2 Te 3 -based compounds and derivatives are milestone materials in the fields of thermoelectrics (TEs) and topological insulators (TIs). They have highly complex band structures and interesting lattice dynamics, which are favorable for high TE performance as well as strong spin orbit and band inversion underlying topological physics. This review presents rational calculations of properties related to TEs and provides theoretical guidance for improving the TE performance of Bi 2 Te 3 -based materials. Although the band structures of these TE materials have been studied theoretically and experimentally for many years, there remain many controversies on band characteristics, especially the locations of band extrema and the exact values of bandgaps. Here, the key factors in the theoretical investigations of Bi 2 Te 3 , Bi 2 Se 3 , Sb 2 Te 3 , and their solid solutions are reviewed. The phonon spectra and lattice thermal conductivities of Bi 2 Te 3 -based materials are discussed. Electronic and phonon structures and TE transport calculations are discussed and reported in the context of better establishing computational parameters for these V 2 VI 3 -based materials. This review provides a useful guidance for analyzing and improving TE performance of Bi 2 Te 3 -based materials.nologies, including cooling and power generation. [1] They have been attracting increased attention in the last decade as a promising potential solution for harvesting waste heat to produce useful electrical power. The key challenge is to improve the efficiency of TE energy conversion, which is determined by the dimensionless figure of merit zT = S 2 σT/(κ e + κ L ), where S, σ, T, κ e , and κ L are the Seebeck coefficient, electrical conductivity, absolute temperature, and the electronic and lattice components of total thermal conductivity κ, respectively. [2] In order to improve zT, one can increase the numerator S 2 σ, which is also called power factor, and decrease the denominator κ. However, the tradeoff among the three properties makes it difficult to realize a high zT. [3] Since all three properties (S, σ, κ e ) are carrier concentration dependent, optimizations of the carrier concentration are needed for maximizing zT. [4] It is often convenient to evaluate TE materials through several empirical parameters, which can be combined into a term called the quality factor B ∼ N v /m I *κ L , [5] where N v is the band degeneracy and m I * is the inertial mass (m I * is equal to the band effective mass m b * for an isotropic single band). This suggests that high N v with low m b * and low κ L are beneficial for TE performance. However, materials such as Bi 2 Te 3 -based alloys, with the highest known roomtemperature TE performance, have complex band structures that are not well described in effective mass models. More sophisticated treatments involving the actual electronic structure are imperative.Since the discovery of the Seebeck effect, a rapid progress in TEs has been made in the 1950s and 1960s, when the classic TE materials Bi 2 Te 3 , ...

Establishing a sustainable energy supply is necessary for intelligent greenhouse environmental management. Compared with traditional energy, green and eco-friendly energy is more conducive to protecting the agricultural production environment. In this study, a fluorinated superhydrophobic greenhouse film is proposed as a negative triboelectric layer material for the construction of a triboelectric nanogenerator that harvests raindrop energy (RDE-TENG). Moreover, an upgraded configuration is adopted, where the bulk effect between the lower/upper electrode and film replaces the interfacial effect of the liquid−solid interface, thereby promoting charge transfer. The results show that the RDE-TENG can serve as a sustainable energy source for greenhouse temperature and humidity sensors that assists in realizing intelligent control of the environment and guides agricultural production processes. This device exhibits high-voltage and a stable output; thus, it has the potential to replace traditional energy sources, which helps toward realizing a self-powered intelligent greenhouse planting mode.