An Asymmetric Iron‐Based Redox‐Active System for Electrochemical Separation of Ions in Aqueous Media

Electrochemically mediated redox‐active processes are gaining momentum as a promising liquid‐phase separation technology. Compared to conventional systems, they offer potential benefits, such as smaller energy footprints, nondestructive operation, reversibility, and tunability for specific analyte removal, with clear applications to societal and industrial challenges like water treatment and chemical synthesis. An asymmetric Faradaic cell heterogeneously functionalized with a metallopolymer at the anode and a hexacyanoferrate material at the cathode is presented for the first time. The redox‐active species' iron centers enhance the electrosorption of heavy metal oxyanions with up to 98% removal in the ppb range, and offer tunable operating windows as low as ≈0.1 V at ≈1 A m^?2. By avoiding water splitting, the hexacyanoferrate cathode imparts additional advantages, namely a four‐fold reduction in adsorption energy requirements, full suppression of solution pH increase, and the ability to capture redox‐active catalytic anions such as polyoxometalates without altering their bulk oxidation state. This hybrid framework of a polymeric ferrocene anode and crystalline hexacyanoferrate cathode allows for simultaneous and synergistic uptake of anions and cations, respectively, creating a new asymmetric scheme for water‐based separations, with foreseeable future extension to fields such as ion‐sensing, energy storage, and electrocatalysis.     

Alloyable Viscous Fluid for Interface Welding of Garnet Electrolyte to Enable Highly Reversible Fluoride Conversion Solid State Batteries

The garnet-type solid-state Li-metal batteries are promising to develop into the high-energy-density system when coupled with the high-capacity conversion reaction cathodes. However, the high interfacial resistance and poor contact between garnet electrolyte and Li anode are still a challenge. Here, an alloyable viscous fluid strategy is proposed for Li/garnet interface welding to enable highly reversible fluoride conversion solid-state batteries. The super-assembled phenide polymer with liquid metal property can serve as “oily” interlayer to in situ construct an ionic/electronic mixed conduction network by thermal and electrochemical lithiation. The resultant healing effect of contact voids between garnet and Li enables a dramatic reduction of interfacial resistance to 6 Ω cm². The confinement and compaction of conversion products by garnet electrolyte endow the FeF₃ based batteries with long-cycling and high-rate performance (520 and 330 mAh g⁻¹ at 0.2 and 2 C respectively). This ceramic configuration also endows the CuF₂ conversion battery with much better rechargeability (instead as widely known primary battery).     

Hybrid Organic/Inorganic Nanostructures for Highly Sensitive Photoelectrochemical Detection of Dissolved Oxygen in Aqueous Media

Precise, reliable, and remote measurement of dissolved oxygen in aqueous media is of great importance for many industrial, environmental, and biological applications. In particular, photoelectrochemical sensors working in differential mode have recently demonstrated promising properties, in terms of stability, sensitivity, and application potential. Here, a new approach is presented, combining visible light sensitivity, efficient photocurrent generation, and solution‐processed fabrication methods of conjugated polymers, with charge carriers selectivity, energetic alignment favorable to efficient interfacial charge transfer and high surface area achievable by using metal oxide nanostructures. Extensive characterization and optimization of the hybrid organic/inorganic system are carried out, leading to the realization of an oxygen sensor device, based on nanostructured palladium oxide/poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole]/[6,6]phenyl‐C61‐butyric acid methyl ester (PdO/APFO‐3:PCBM) as materials of choice. State‐of‐the‐art sensitivity, amounting at ?5.87 μA cm^?2 ppm^?1, low background signal, in the order of ?4.85 μA cm^?2, good electrochemical stability for more than 2 h of continuous functioning and high reproducibility of the signal over the pH 1 to 10 range, are reported, making the hybrid device suitable for several practical uses. The results fully validate the mixed organic/inorganic approach for photoelectrochemical applications, and pave the way for its further exploitation in fields like waste water treatment, environmental monitoring, and water splitting.     

水质的光学遥感监测技术

简要介绍了水质光学遥感监测技术的基本原理，从地面、航空及卫星遥感三个方面，综述了水质遥感监测技术的研究和应用现状。     

Biocompatible Blends of an Intrinsically Conducting Polymer as Stretchable Strain Sensors for Real-Time Monitoring of Starch-Based Food Processing

Because stretchable strain sensors that have a resistance or capacitance sensitive to strain can sense skin deformation during physical movement, they have been extensively studied as wearable devices for healthcare monitoring. In principle, they can be used to monitor starch-based food processing in real time, since starch-based food can have remarkable volume change during processing. Monitoring starch-based food processing in real time can help achieve high quality and high productivity while reducing energy consumption. Nevertheless, there is no such report in the literature. Here, a blend of starch and a biocompatible intrinsically conducting polymer, poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS), is reported as a stretchable strain sensor to monitor starch-based food processing including fermentation, steaming, storage, and refreshing in a real-time manner. The resistance of the blends increases during the food volume expansion mainly caused by the fermentation, steaming, and refreshing, and it decreases as a result of the food volume shrinkage during cooling or storage. The signals can be thus used to optimize the processing conditions and control the food quality. This technology can be easily combined with the Internet of Things.     

一种嵌入式净水系统在线水质监测装置的研发

设计完成了一种适用于末端净水系统的嵌入式在线水质监测装置。选用280 nm波长的深紫外LED激发溶解性有机物腐殖质类荧光团产生发射波长在400 nm^500 nm范围内的荧光,将探测的荧光和散射光信号通过跨阻运放和低通滤波电路后,送入微处理器进行模数转换和数据处理。采用国际腐殖质协会自然有机物标准品配制溶液测试,结果发现监测装置的荧光信号值与溶解性有机碳浓度呈现出良好的线性关系,且具有响应快速、灵敏度高和功耗低等优点。