The growing energy demand with the widespread use of smart portable electronics, as well as an exponential increase in demand for smart batteries for electric vehicles, entails the development of ...efficient portable batteries with high energy density and safe power storage systems. Li-ion batteries arguably have superior energy density to all other traditional batteries. Developing mechanically robust solid-state electrolytes (SSEs) for lithium-ion conduction for an efficient portable energy storage unit is vital to empower this technology and overcome the safety constraints of liquid electrolytes. Herein, we report the formation of self-assembled organic nanosheets (SONs) utilizing positional isomers of small organic molecules (AM-2 and AM-3) for use as SSEs for lithium-ion conduction. Solvent-assisted exfoliation of the bulk powder yielded SONs having near-atomic thickness (∼4.5 nm) with lateral dimensions in the micrometer range. In contrast, self-assembly in the DMF/water solvent system produced a distinct flower-like morphology. Thermodynamic parameters, crystallinity, elemental composition, and nature of H-bonding for two positional isomers are established through various spectroscopic and microscopic studies. The efficiency of the lithium-ion conducting properties is correlated with factors like nanostructure morphology, ionic scaffold, and locus of the functional group responsible for forming the directional channel through H-bonding in the positional isomer. Amongst the three different morphologies studied, SONs display higher ion conductivity. In between the cationic and zwitterionic forms of the monomer, integration of the cationic scaffold in the SON framework led to higher conductivity. Amongst the two positional isomers, the
meta
-substituted carboxyl group forms a more rigid directional channel through H-bonding to favor ionic mobility and accounts for the highest ion conductivity of 3.42 × 10
−4
S cm
−1
with a lithium-ion transference number of 0.49 at room temperature. Presumably, this is the first demonstration that signifies the importance of the cationic scaffold, positional isomers, and nanostructure morphologies in improving ionic conductivity. The ion-conducting properties of such SONs having a guanidinium-core may have significance for other interdisciplinary energy-related applications.
Self-assembled organic nanosheets (SONs) having a near-atomic thickness (∼4.5 nm) are obtained through exfoliation. Among two positional isomers of the guanidinium-core analogue used for SONs, one shows greatly improved Li
+
ion conductivity.
Detection and differentiation of explosives is an issue of immediacy for security and environmental monitoring. At present, the most operated explosive system combines primary and secondary ...explosives. Although various advances are presently equipped for identifying primary explosives, the insensitive nature of secondary explosives makes their detection and differentiation challenging. Here, we report three coordination nanosheets (CNs) AM-8-Eu, AM-8-Tb, and AM-8-Zn containing three-way terpyridine ligands (AM-8) and Eu(III), Tb(III), and Zn(II) ions. These CNs act as a highly selective platform for detecting unexplored high-energy explosive 1,1-Diamino-2,2-dinitro ethylene (FOX-7) in solid and solution phases. For AM-8-Zn, calculated molecular electrostatic surface potential revealed two modes of interactions for triaminotrinitrobenzene (TATB) and FOX-7, producing two distinct spectral responses. Digital analysis of these responses revealed a complimentary implication (IMP)/not implication (NIMP) logic function. Finally, the unique feature of IMP gate is used to define all possible sixteen distinct binary Boolean operations on two logic values for “functional completeness”. The detection and differentiation of such insensitive high-energy explosives TATB and FOX-7, where Boolean logic can process information through distinct binary responses in solid and solution phases, have not been witnessed hitherto in a single chemical platform.
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•Three novel luminescent coordination nanosheets (CNs) were prepared.•Detection and differentiation of unexplored high-energy explosive FOX-7 and TATB performed in solid and solution phases.•DFT study revealed different ESPs of the CNs favor two different modes of interaction with TATB and FOX-7.•Digital analysis revealed a complimentary implication (IMP)/not implication (NIMP) logic function.•Unique feature of IMP gate is used to define “functional completeness”.
Electrocatalytic water splitting provides a sustainable method for storing intermittent energies, such as solar energy and wind, in the form of hydrogen fuel. However, the oxygen evolution reaction ...(OER), constituting the other half-cell reaction, is often considered the bottleneck in overall water splitting due to its slow kinetics. Therefore, it is crucial to develop efficient, cost-effective, and robust OER catalysts to enhance the water-splitting process. Transition-metal-based coordination polymers (CPs) serve as promising electrocatalysts due to their diverse chemical architectures paired with redox-active metal centers. Despite their potential, the rational use of CPs has faced obstacles including a lack of insights into their catalytic mechanisms, low conductivity, and morphology issues. Consequently, achieving success in this field requires the rational design of ligands and topological networks with the desired electronic structure. This study delves into the design and synthesis of three novel conjugated coordination polymers (CCPs) by leveraging the full conjugation of terpyridine-attached flexible tetraphenylethylene units as electron-rich linkers with various redox-active metal centers Co(II), Ni(II), and Zn(II). The self-assembly process is tuned for each CCP, resulting in two distinct morphologies: nanosheets and nanorings. The electrocatalytic OER performance efficiency is then correlated with factors such as the nanostructure morphology and redox-active metal centers in alkaline electrolytes. Notably, among the three morphologies studied, nanorings for each CCP exhibit a superior OER activity. Co(II)-integrated CCPs demonstrate a higher activity between the redox-active metal centers. Specifically, the Co(II) nanoring morphology displays exceptional catalytic activity for OER, with a lower overpotential of 347 mV at a current density of 10 mA cm–2 and small Tafel slopes of 115 mV dec–1. The long-term durability is demonstrated for at least 24 h at 1.57 V vs RHE during water splitting. This is presumably the first proof that links the importance of nanostructure morphologies to redox-active metal centers in improving the OER activity, and it may have implications for other transdisciplinary energy-related applications.
Crystalline two-dimensional organic nanosheets (2D-ONs) having atomic or near-atomic thickness with infinite lateral dimensions are of crucial significance for their possible application as a ...material for energy storage. The presence of nanofluidic channels with a designed array of molecular interlayers in such 2D-ONs, for a favorable lithium-ion transport, has special significance for improving the efficacy of lithium-ion batteries. However, the rational design of crystalline 2D-ONs remains a challenge because of the lack of appropriate monomers and convenient preparation methods. Herein, we report a unique lithium-ion conducting behavior of zwitterionic 2D-ONs, formed through self-assembly of a small organic molecule AM-1. Different microscopic studies confirm the near-atomic thickness (∼3.5 nm) of these 2D-ONs. Results of the single-crystal X-ray diffraction studies confirm the presence of a one-dimensional (1D) channel in crystalline 2D-ONs, which was generated during the self-assembly process of the zwitterionic monomer scaffold. The presence of immobilized ionic centers with well-defined directional channels in the 2D-ONs favors the transportation of lithium ions with a room-temperature lithium-ion conductivity of 5.14 × 10–5 S cm–1, which is rather unique for self-assembled 2D-ONs.
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