Rapid, on-site measurement of ppm-level humidity in real time remains a challenge. In this work, we fabricated a few micrometer thick, β -ketoenamine-linked covalent organic framework (COF) membrane via interfacially...
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Rapid, on-site measurement of ppm-level humidity in real time remains a challenge. In this work, we fabricated a few micrometer thick, β -ketoenamine-linked covalent organic framework (COF) membrane via interfacially confined condensation of 1,3,5-tris-(4-aminophenyl)triazine (TTA) with 1,3,5-tri-formylphloroglucinol (TP). Based on the super-sensitive and reversible response of the COF membrane to water vapor, we developed a high-performance film-based fluorescence humidity sensor, depicting unprecedented detection limit of 0.005 ppm, fast response/recovery (2.2 s/2.0 s), and a detection range from 0.005 to 100 ppm. Remarkably, more than 7,000-time continuous tests showed no observable change in the performance of the sensor. The applicability of the sensor was verified by on-site and real-time monitoring of humidity in a glovebox. The superior performance of the sensor was ascribed to the highly porous structure and unique affinity of the COF membrane to water molecules as they enable fast mass transfer and efficient utilization of the water binding sites. Moreover, based on the remarkable moisture driven deformation of the COF membrane and its composition with the known polyimide films, some conceptual actuators were created. This study brings new ideas to the design of ultra-sensitive film-based fluorescent sensors (FFSs) and high-performance actuators.
Obesity and its co-morbidities such as diabetes,coronary heart disease and cancer are a fast growing health threat in today' s *** great efforts,pharmacotherapy of obesity has achieved little success to ***,novel ...
Obesity and its co-morbidities such as diabetes,coronary heart disease and cancer are a fast growing health threat in today' s *** great efforts,pharmacotherapy of obesity has achieved little success to ***,novel targets for body weight control are a pressing need in order to fight this *** receptor subtype-3 (BRS3) is a G-protein coupled receptor whose natural ligand remains ***3 is primarily expressed in the brain,particularly in the hypothalamus,a key center from controlling energy *** devoid of the BRS3 gene (knock-out) develop obesity and *** discovered novel,potent and selective BRS3 agonists that enable exploration of BRS3 biological function in vivo.
The electrochemical CO 2 reduction reaction (ECR) is a promising pathway to producing valuable chemicals and fuels. Despite extensive studies reported, improving CO 2 adsorption for local CO 2 enrichment or water diss...
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The electrochemical CO 2 reduction reaction (ECR) is a promising pathway to producing valuable chemicals and fuels. Despite extensive studies reported, improving CO 2 adsorption for local CO 2 enrichment or water dissociation to generate sufficient H* is still not enough to achieve industrial-relevant current densities. Herein, we report a “two-in-one” catalyst, defective Bi nanosheets modified by CrO x (Bi−CrO x ), to simultaneously promote CO 2 adsorption and water dissociation, thereby enhancing the activity and selectivity of ECR to formate. The Bi−CrO x exhibits an excellent Faradaic efficiency (≈100 %) in a wide potential range from −0.4 to −0.9 V. In addition, it achieves a remarkable formate partial current density of 687 mA cm −2 at a moderate potential of −0.9 V without iR compensation, the highest value at −0.9 V reported so far. Control experiments and theoretical simulations revealed that the defective Bi facilitates CO 2 adsorption/activation while the CrO x accounts for enhancing the protonation process via accelerating H 2 O dissociation. This work presents a pathway to boosting formate production through tuning CO 2 and H 2 O species at the same time.
The hydrazine oxidation-assisted H 2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) i...
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The hydrazine oxidation-assisted H 2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N−C/Ru NSA , merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N−C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring −80 mV and −9 mV respectively to reach 10 mA cm −2 . Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H ad/desorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N−C/Ru NSA excels as both anode and cathode materials, achieving 10 mA cm −2 at just 64 mV. The zinc hydrazine (Zn−Hz) battery assembled with α-MoC/N−C/Ru NSA cathode and Zn foil anode can exhibit 97.3 % energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn−Hz with OHzS system enables self-powered H 2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.
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