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On-chip micro-supercapacitors (MSCs) are important Si-compatible power-source backups for miniaturized electronics. Despite their tremendous advantages, current on-chip MSCs require harsh processing conditions and typically perform like resistors when filtering ripples from alternating current (AC). Herein, we demonstrated a facile layer-by-layer method towards on-chip MSCs based on an azulene-bridged coordination polymer framework (PiCBA). Owing to the good carrier mobility (5×10−3 cm2 V−1 s−1) of PiCBA, the permanent dipole moment of azulene skeleton, and ultralow band gap of PiCBA, the fabricated MSCs delivered high specific capacitances of up to 34.1 F cm−3 at 50 mV s−1 and a high volumetric power density of 1323 W cm−3. Most importantly, such MCSs exhibited AC line-filtering performance (−73° at 120 Hz) with a short resistance-capacitance constant of circa 0.83 ms. [ABSTRACT FROM AUTHOR]

Carbon electrocatalysts consisting of metal complexes such as MN x or MS x are promising alternatives to high-cost Pt catalysts for the hydrogen evolution reaction (HER). However, the exact HER active sites remain elusive. Here, molecular metal dithiolene-diamine (MS2N2, M=Co and Ni), metal bis(dithiolene) (MS4), and metal bis(diamine) (MN4) complexes were selectively incorporated into carbon-rich 2D metal-organic frameworks (2D MOFs) as model carbon electrocatalysts. The 2D MOF single layers, powders, and composites with graphene were thus prepared and showed definite active sites for H2 generation. The electrocatalytic HER activity of the 2D MOF-based catalysts with different metal complexes follow the order of MS2N2>MN4>MS4. Moreover, the protonation preferentially occurred on the metal atoms, and the concomitant heterolytic elimination of H2 was favored on the M-N units in the MS2N2 active centers. The results provide an in-depth understanding of the catalytic active sites, thus making way for the future development of metal complexes in carbon-rich electrode materials for energy generation. [ABSTRACT FROM AUTHOR]

To achieve sustainable production of H2 fuel through water splitting, low-cost electrocatalysts for the hydrogen-evolution reaction (HER) and the oxygen-evolution reaction (OER) are required to replace Pt and IrO2 catalysts. Herein, for the first time, we present the interface engineering of novel MoS2/Ni3S2 heterostructures, in which abundant interfaces are formed. For OER, such MoS2/Ni3S2 heterostructures show an extremely low overpotential of ca. 218 mV at 10 mA cm−2, which is superior to that of the state-of-the-art OER electrocatalysts. Using MoS2/Ni3S2 heterostructures as bifunctional electrocatalysts, an alkali electrolyzer delivers a current density of 10 mA cm−2 at a very low cell voltage of ca. 1.56 V. In combination with DFT calculations, this study demonstrates that the constructed interfaces synergistically favor the chemisorption of hydrogen and oxygen-containing intermediates, thus accelerating the overall electrochemical water splitting. [ABSTRACT FROM AUTHOR]

Viscoelastic vesicle gels were prepared by mixing a nonionic surfactant, tetraethylene glycol monododecyl ether (C12EO4), and an anionic dye, sodium 4-phenylazobenzoic acid (AzoNa). The gels, which were composed of multilamellar vesicles, were analyzed by cryogenic transmission electron microscopy (cryo-TEM), freeze-fracture transmission electron microscopy (FF-TEM), 2H NMR spectroscopy, and small-angle X-ray scattering (SAXS). The mechanism of vesicle-gel formation is explained by the influence of anionic molecules on the bilayer bending modulus. Interestingly, the vesicle gels were observed to be sensitive to temperature, pH, and light. The viscoelastic vesicle gels respond to heat; they thin at lower temperatures and become thicker at higher temperatures. The vesicle gels are only stable from pH 7 to 11, and the gels become thinner outside of this range. UV light can also trigger a structural phase transition from micelles to multilamellar vesicle gels. [ABSTRACT FROM AUTHOR]

Honeycomb-patterned films (HPFs)of Au nanoparticles (Au NPs) withpore size controlled by varying the quantity of Au NPs or using modifiedagents of different mercaptans (C14H29SH, C16H33SH, and C18H37SH) wereprepared. The strength of the HPFs containing Au NPs can be enhancedbecause of the addition of polymers including polystyrene, poly(l-lactic acid), and poly(methyl methacrylate-co-ethyl acrylate). With an increase in the amount of polymer and thenumber of Au NPs or the chain length of the modified agents, the poresize of HPFs decreases, indicating that the pore size can be wellcontrolled by adjusting the above factors. Interestingly, HPFs withelliptical pores that were created by the direction of the air flowwere observed. The pore diameter on the outer rim is smaller thanthat in the center, which should be because of the subordinate evaporationof the solvent in the center. Sponge structures were observed in thecross sections of the walls of HPFs, which should be produced by microphaseseparation. The HPFs consisting of Au NPs with controllable pore sizeexhibited stronger surface-enhanced Raman scattering. We believe thatthe HPFs composed of metal NPs such as Au, Ag, and Cu are exploitedin multispectral scanners, nanophotons, and sensors. [ABSTRACT FROM AUTHOR]

Aluminium laurate [AI(00CC11H23)3] was synthesized as a surfactant, which can dissolve in micellar solution of a zwitterionic surfactant, tetradecycldimethylamine oxide (C14DMAO). The phase behavior of the mixtures of Al(00CC11H23)3 and C14DMAO in water was studied and birefringent Lα-phase was observed. The birefringent Lα-phase consists of vesicles that were demonstrated by Polarizer and Transmission Electron Microscope (TEM) micrographs. Al3+-coordinated vesicles could be used as templating-precursor, providing a vesicle-route for preparation of inorganic nanoscale particles. [ABSTRACT FROM AUTHOR]

High-quality patterning determines the properties of patterned emerging two-dimensional (2D) conjugated polymers and is essential for potential applications in future electronic nanodevices. However, the most suitable patterning method for 2D polymers has yet to be determined because we still do not have a comprehensive understanding of their damage mechanisms by visualizing the structural modification that occurs during the patterning process. Here, the damage mechanisms during patterning of 2D polymers, induced by various patterning methods, are unveiled based on a systematic study of structural damage and edge morphology in an imine-based 2D polymer (polyimine). Patterning using a focused electron beam, focused ion beam (FIB) and mechanical carving is evaluated. The focused electron beam successively introduces a sputtering effect, knock-on displacement damage and massive radiolysis with increasing electron dose from 9.46 × 10 7 electrons nm − 2 to 1.14 × 10 10 electrons nm − 2 . Successful patterning is enabled by knock-on damage but impeded by carbon contamination beyond a critical sample thickness. A FIB creates current-dependent edge morphologies and extensive damage from ion implantation caused by the tail of the unfocused beam. A precisely controlled tip can tear the polyimine film through grain boundaries and hence create a patterning edge with suitable edge roughness for certain application scenarios when beam damage is avoided. Taking structural damage and the resulting quantitative edge roughness into consideration, this study provides a detailed instruction on the proper patterning techniques for 2D crystalline polymers and paves the way for tailored intrinsic properties and device fabrication using these novel materials. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are prized for their selective dissolution of carbon dioxide (CO2), leading to their widespread use in ionogel membranes for gas separation. Despite their advantages, creating sustainable ionogel membranes with high IL contents poses challenges due to limited mechanical strength, leakage risks, and poor recyclability. Herein, we leverage copolymerized and supramolecularly bound ILs to develop ionogel membranes with high mechanical strength, zero leakage, and excellent self‐healing and recycling capabilities. These membranes exhibit superior ideal selectivity for gas separation compared to other reported ionogel membranes, achieving a CO2/nitrogen selectivity of 61.7 and a CO2/methane selectivity of 24.6, coupled with an acceptable CO2 permeability of 186.4 Barrer. Additionally, these gas separation ionogel membranes can be upcycled into ionic skins for sensing applications, further enhancing their utility. This research outlines a strategic approach to molecularly engineer ionogel membranes, offering a promising pathway for developing sustainable, high‐performance materials for advanced gas separation technologies. [ABSTRACT FROM AUTHOR]

2D conjugated metal–organic frameworks (2D c‐MOFs) are emerging as unique electroactive materials for electronics and spintronics. The structural design and discovery of Kagome‐type 2D c‐MOFs exhibiting a metallic state are of paramount significance, yet remain rarely explored. Here, the solution synthesis of benzenehexol‐based 2D c‐MOFs based is presented on the tetrahydroxy‐1,4‐quinone (THQ) ligand. This study shows that controlling the pH of the reaction system to ≈7.5 yields an energetically favorable nonporous Cu3(C6O6) with a Kagome lattice, while at a pH of ≈10, the known porous Cu3(C6O6)2 with a honeycomb lattice is obtained. The crystal structures of both Cu3(C6O6)2 and Cu3(C6O6) are resolved with near‐atomic precision (resolution, 1.8 Å) using an imaging technique. Unlike the p‐type semiconducting behavior of Cu3(C6O6)2, theoretical studies identify Cu3(C6O6) as a metal due to its unique structural topology. The metallic state of Cu3(C6O6) is experimentally validated by terahertz time‐domain spectroscopy (THz‐TDS), which shows an increase in conductivity upon cooling. Scattering‐type scanning near‐field optical microscopy (s‐SNOM) measurements further support these findings by revealing an increase in normalized reflectivity with decreasing temperature. This work provides a new avenue for tailoring the structural topology of 2D c‐MOFs to attain the Kagome lattice and metallic state. [ABSTRACT FROM AUTHOR]

Two‐dimensional polymers (2DPs) and their layer‐stacked 2D covalent organic frameworks have recently emerged as nonlinear optical (NLO) materials for potential applications in optics. However, the chemistry for designing third‐order NLO 2DP films with large nonlinear absorption coefficient (β) has remained a mystery. Herein, three highly crystalline porphyrin‐integrated 2D polyimines (named as 2DPI‐Zn‐Azo, 2DPI‐2H‐Azo, and 2DPI‐Zn), which are homogeneous films showing large lateral areas over cm2, uniform transparency, and thickness of tens of nanometers are reported. Particularly, the 2DPI‐Zn‐Azo film comprising zinc porphyrin and –NN– displays a large saturable absorption under 532 nm and the highest β (−1.88 × 105 cm GW−1) among the three 2D polyimines, that is also 2–5 orders of magnitude higher than the state‐of‐art performance of photoactive small molecules, porphyrin‐integrated 2DPs, and inorganic 2D materials. Control experiments in combination with theoretical calculation discover that the embedding of metal centers and –NN– results in highly delocalized π‐electrons and narrow bandgap in 2DPI‐Zn‐Azo, which enables fast transfer of the photogenerated electrons after the light‐excited charge separation, thus boosting the NLO performance. This work opens up a new path for the construction of highly efficient third‐order NLO film materials, and pushes the development of 2DPs for optics and optoelectronics. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]