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Some gas sensors exhibit significant increases in their sensitivity and response/recovery rates under light illumination. This photoactivation of the gas response is considered a promising alternative to conventional thermal activation, which requires high power consumption. Thin layers of molybdenum disulfide (MoS2) are known to exhibit an effective photoactivated gas response under visible light. However, the mechanism of the photoactivated response has not yet been studied in detail. In this study, we fabricated field-effect-transistor (FET) gas sensors based on MoS2 monolayers and investigated their photoactivated gas responses to NO2 gas under illumination at various irradiances of visible light. A photocurrent was generated mainly due to the photovoltaic effect, which decreased upon exposure to NO2. The conductance-based sensor response showed a dependence on NO2 concentration according to the Langmuir adsorption isotherm, thereby suggesting that the response is proportional to the surface coverage of NO2 molecules on the MoS2 layer. The response and recovery rates showed a linear increase with increasing irradiance. Analysis based on the Langmuir adsorption model revealed that both photostimulated adsorption and desorption are involved in the photoactivated response. In contrast, despite the strong dependence of the photocurrent on the irradiance, the magnitude of the sensor response was independent of the irradiance. Based on this result and the change in transfer characteristics of the FET during NO2 exposure, we concluded that the fast response/recovery of the photoactivated response is due to the carrier mobility modulation of MoS2, which is caused by the dipole scattering of adsorbed NO2 molecules.PbGa6Te10 is a promising thermoelectric (TE) material due to its ultralow thermal conductivity and moderated values of the Seebeck coefficient. However, the reproducible synthesis of the PbGa6Te10-based materials for the investigation and tailoring of physical properties requires detailed knowledge of the phase diagram of the system. With this aim, a combined thermal, structural, and microstructural study of the Pb-Ga-Te ternary system near the PbGa6Te10 composition is presented here, in which polycrystalline samples with the compositions (PbTe)1-x(Ga2Te3) x (0.67 ≤ x ≤ 0.87) and Pb y Ga6Te10 (0.85 ≤ y ≤ 1.5) were synthesized and characterized. Differential scanning calorimetry measurements revealed that PbGa6Te10 melts incongruently at 1007 ± 2 K and has a polymorphic phase transition at 658-693 K depending on composition. Powder X-ray diffraction of annealed samples confirmed that below 658 K, the trigonal modification of PbGa6Te10 exists (space groups P3121 or P3221) and above 693 K, the rhombohedral one (ws that the knowledge of phase equilibria and crystal chemistry plays a key role in improving the energy conversion efficiency for new functional TE materials.A scalable logic platform made up of multilayer DNA circuits was constructed using Pb2+, Cu2+, and Zn2+ as the three inputs and three different fluorescent signals as the outputs. DNAzyme-guided cyclic cleavage reactions and DNA toehold-mediated strand branch migration were utilized to organize and connect nucleic acid probes for building the high-level logic architecture. The sequence communications between each circuit enable the logic network to work as a keypad lock, which is an information protection model at the molecular level. The multi-output mode was used to monitor the gradual unlocking process of the security system, from which one can determine which password is correct or not immediately. The autocatalytic cleavage of DNAzyme makes the biocomputing circuit feasible to realize the reset function automatically without external stimuli. Importantly, the logic platform is robust and can work effectively even in complex environmental samples.The conversion of CO2 into high value-added chemical products is the focus of current scientific research. We make use of the specific porous structure of nanosized metal-organic frameworks (MOFs) loading the highly active yet metastable nano Cu2O to catalyze the conversion of CO2 into a series of high value-added bioactive pyridone/pyrone-3-carboxylic acid products via heterocyclic 4-hydroxy-2-pyridones/pyrones, which exhibit high activity, selectivity, and reusability. Nano MOF sponge-covered metastable nanoparticles (NPs) converting CO2 into high value-added bioproducts provide a facile "dual-side surfactant" strategy, a highly efficient composite catalyst, and a practicable pathway not only for the sustainable use of CO2 but also for environment-friendly production of bioproducts.Herein, thermoelectric carbon nanoparticle (CNP)-carbon nanotube (CNT) heterostructures are introduced as a promising flexible thermoelectric material. The optimal barrier energy between the CNP and CNT increases the Seebeck coefficient (S) of the heterostructures through the energy filtering effect. For optimized thermoelectric performance, the CNP-CNT barrier energy can be effectively tuned by controlling the work function of the CNPs. The optimized p-type CNP-CNT heterostructures exhibited S and power factor (PF) of 50.6 ± 1.4 μV K-1 and 400 ± 26 μW m-1 K-2, respectively. The n-type CNP-CNT heterostructures, optimized for another work function of the CNPs, exhibited S and PF of up to -37.5 ± 3.4 μV K-1 and 214 ± 42 μW m-1 K-2, respectively. The energy harvesting capability of a thermoelectric generator prepared using p- and n-type CNP-CNT heterostructures with optimized barrier energies is demonstrated. The thermoelectric generator with 10 p-type and 9 n-type thermoelectric elements exhibited a maximum output power of 0.12 μW from a ΔT of 5 K. Selleckchem SIS17 This work shows a facile strategy for synthesizing thermoelectric CNP-CNT heterostructures with optimized energy filtering effects. Application to the thermoelectric device on a paper substrate is also discussed.More and more attention has been focused on Ni-rich ternary materials due to their superior specific capacity, but they still suffer inherent structural irreversibility and rapid capacity degradation under a high voltage. Oxidation of unstable oxygen will lead to the irreversible transformation of the structure. Taking into account the strong W-O bond, an appropriate amount of W-doping is studied to reinforce the thermal stability and electrochemical performance of LiNi0.6Co0.2Mn0.2O2 (NCM622) at 4.5 V. Combining experiments and theoretical calculations, it can be found that W-doping is most preferred at Co sites, and the average charge around O in the NiO6 octahedron becomes more negative after W-doping, which can successfully restrain the release of oxygen, thereby improving the stability of the crystal structure during deep delithiation. In addition, W-doping decreases the energy barrier of the Li+ migration slightly and boosts the kinetic diffusion of lithium ions. As a result, NCM622 doped with 0.5% W boasts an outstanding capacity retention of 96.
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