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For the first time, the dominant magnetoelectric activity of ZIF-67-derived carbonaceous microparticles embedded with Co nanoparticles and distinctive magnetothermal effect of MIL-88B-derived Fe3O4 nanocubes decorated on carbonaceous microrods, respectively, were explored to be controlled by the structure of the MOF-derived electrically conductive carbonaceous matrix and metal nanoparticles. [ABSTRACT FROM AUTHOR]

The current bottleneck in the development of efficient photocatalysts for hydrogen evolution is the limited availability of high‐performance acceptor units. Over the past nine years, dibenzo[b,d]thiophene sulfone (DBS) has been the preferred choice for the acceptor unit. Despite extensive exploration of alternative structures as potential replacements for DBS, a superior substitute remains elusive. In this study, a symmetry‐breaking strategy was employed on DBS to develop a novel acceptor unit, BBTT‐1SO. The asymmetric structure of BBTT‐1SO proved beneficial for increasing multiple moment and polarizability. BBTT‐1SO‐containing polymers showed higher efficiencies for hydrogen evolution than their DBS‐containing counterparts by up to 166 %. PBBTT‐1SO exhibited an excellent hydrogen evolution rate (HER) of 222.03 mmol g−1 h−1 and an apparent quantum yield of 27.5 % at 500 nm. Transient spectroscopic studies indicated that the BBTT‐1SO‐based polymers facilitated electron polaron formation, which explains their superior HERs. PBBTT‐1SO also showed 14 % higher HER in natural seawater splitting than that in deionized water splitting. Molecular dynamics simulations highlighted the enhanced water‐PBBTT‐1SO polymer interactions in salt‐containing solutions. This study presents a pioneering example of a substitute acceptor unit for DBS in the construction of high‐performance photocatalysts for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production through water splitting provides a promising route towards renewable energy generation. However, constructing photocatalytically active covalent organic frameworks with high charge separation remains challenging. Herein, we demonstrate for the first time the use of 2D imide–imine-based covalent organic frameworks as new photocatalysts for the hydrogen evolution reaction (HER) under visible light irradiation. The main achievement is incorporating donor and dual acceptors, including weak electron-deficient imine and strong electron-deficient imide groups within the 2D COF backbone that create favorable push–pull–pull intramolecular charge transfer to promote charge separation after photoexcitation. DFT and NBO calculations revealed the strong integration of donor and dual acceptors with a synergistic interplay enhancing spatial charge transfer and separation. The synthesized COFs show significantly high thermal stability >400 °C with a high energy barrier for degradation. Moreover, Py-DNII-COF exhibited a 104-fold enhancement in hydrogen evolution compared to TFPB-DNII-COF. Py-DNII-COF demonstrated excellent stability and hydrogen evolution of 625 μmol h−1 g−1 over 48 hours. [ABSTRACT FROM AUTHOR]

Human skin relies on cutaneous receptors that output digital signals for tactile sensing in which the intensity of stimulation is converted to a series of voltage pulses. We present a power-efficient skin-inspired mechanoreceptor with a flexible organic transistor circuit that transduces pressure into digital frequency signals directly. The output frequency ranges between 0 and 200 hertz, with a sublinear response to increasing force stimuli that mimics slow-adapting skin mechanoreceptors. The output of the sensors was further used to stimulate optogenetically engineered mouse somatosensory neurons of mouse cortex in vitro, achieving stimulated pulses in accordance with pressure levels. This work represents a step toward the design and use of large-area organic electronic skins with neural-integrated touch feedback for replacement limbs.

The escalating global scarcity of water resources has amplified the need to develop efficient desalination methods. Electrochemical deionization (ECDI) has emerged as a promising method to solve this pressing issue. Among various ECDI systems, conducting polymers have showcased remarkable potential for electrode materials due to their facile large-scale synthesis and precise control over the removal of anions and cations. We scrutinized the impact of diverse dopant sizes on the intrinsic properties of polypyrrole (PPy) chains, leading to the development of a high-performance ECDI system. Incorporation of para-substituted groups featuring elongated carbon chains, such as dodecylbenzene sulfonate (DBS), the PPy-DBS-1//PPy-ClO4 configuration attained a salt-adsorption capacity (SAC) of 61.7 mg g−1 in NaCl solution (10 mM) and sustained low energy consumption (0.22 kW h/kg-NaCl). Our findings suggest that the size and type of dopant have key roles in enhancing the ion transport and mobility of charge carriers within the conducting-polymer framework. Moreover, fine-tuning the doping ratio enhanced the cation-capture ability of electrodes and sustained their cycling stability. Overall, these insights into the symbiotic relationship between dopants and PPy framework within an ECDI system provide guidance framework for augmenting the electrode performance of conducting polymers with dopants, and expanding the potential applications of conducting polymers in ECDI. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production (PHP) from water is a promising solution for environmental pollution due to its high energy density and the abundant availability of water and solar energy on Earth. 1,1-dicyanomethylene-3-indanone (IC) has been widely used as an end group in organic photovoltaics owing to its strong electron-withdrawing ability and planarity. However, research on the application of IC structures in PHP is limited due to synthesis challenges. In this study, we designed a series of novel IC-based monomers incorporating a dibenzothiophene-S,S-dioxide unit through Suzuki coupling. These monomers were used to synthesize polymers with varying degrees of malononitrile substitution, referred to as ICFTDB, ICTDB, and IDMTDB. We investigated the correlation between the optical, electrochemical, and hydrogen evolution performances of these polymers. Through transient absorption spectroscopy, we demonstrated that ICTDB exhibited enhanced capabilities for ultrafast electron transfer and reduced recombination effects. As a result, ICTDB, photocatalysts with IC-containing structures achieved a hydrogen evolution rate of 30.0 mmol g−1 h−1, which was 11.5 times higher than that of ICFTDB, the polymer with no malononitrile substitution. This study provides valuable insights into the potential of IC-based conjugated polymers for photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

Ten ionic manganese(II) complexes of [EMIm]2[MnX2Y2] (EMIm=1‐ethyl‐3‐methylimidazolium ion; X, Y=Cl, Br or I) and [BnMIm]2[MnX2Y2] (BnMIm=1‐benzyl‐3‐methylimidazolium ion; X, Y=Cl, Br or I) types were synthesized and studied in terms of their thermal and photophysical properties. Complexes with [BnMIm]+ cation were found to exhibit higher crystallinity, owing to the aromatic π‐stacking, and superior photoluminescent quantum yields, promoted by the increased Mn⋅⋅⋅Mn distance. For complexes with chlorine and bromine ligands efficient tunability of photophysical parameters was demonstrated. Out of all complexes, [BnMIm]2[MnBr4] was found to have the highest photoluminescence quantum yield at room temperature (Φ=0.59). To highlight the importance of a large Mn⋅⋅⋅Mn distance for achieving high Φ values, a mixed‐anion analog of complex [BnMIm]2[MnBr4] was prepared, with the suggested formula of [BnMIm]4[MnBr4]Br2. The latter have shown a significant improvement in d–d absorption efficiency and a reduction in nonradiative deactivation, which led to an outstanding Φ value of 0.97. Finally, the optical band gap of [BnMIm]4[MnBr4]Br2 was estimated to describe its applicability as light‐emitting material. [ABSTRACT FROM AUTHOR]