@article {49003,
	title = {Morphology tuning via linker modulation: metal-free covalent organic nanostructures with exceptional chemical stability for electrocatalytic water splitting},
	journal = {Advanced Materials },
	volume = {36},
	year = {2024},
	month = {MAR},
	type = {Article},
	abstract = {<p>
	The development of synthetic routes for the formation of robust porous organic polymers (POPs) with well-defined nanoscale morphology is fundamentally significant for their practical applications. The thermodynamic characteristics that arise from reversible covalent bonding impart intrinsic chemical instability in the polymers, thereby impeding their overall potential. Herein, a unique strategy is reported to overcome the stability issue by designing robust imidazole-linked POPs via tandem reversible/irreversible bond formation. Incorporating inherent rigidity into the secondary building units leads to robust microporous polymeric nanostructures with hollow-spherical morphologies. An in-depth analysis by extensive solid-state NMR (1D and 2D) study on H-1, C-13, and N-14 nuclei elucidates the bonding and reveals the high purity of the newly designed imidazole-based POPs. The nitrogen-rich polymeric nanostructures are further used as metal-free electrocatalysts for water splitting. In particular, the rigid POPs show excellent catalytic activity toward the oxygen evolution reaction (OER) with long-term durability. Among them, the most efficient OER electrocatalyst (TAT-TFBE) requires 314 mV of overpotential to drive 10 mA cm(-2) current density, demonstrating its superiority over state-of-the-art catalysts (RuO2 and IrO2).</p>
},
	keywords = {bi-functional electrocatalysts, chemically robust, hollow-spherical morphologies, imidazole-linked, inherent rigidity, metal-free, water splitting},
	issn = {0935-9648},
	doi = {10.1002/adma.202209919},
	author = {Karak, Shayan and Koner, Kalipada and Karmakar, Arun and Mohata, Shibani and Nishiyama, Yusuke and Duong, Nghia Tuan and Thomas, Neethu and Ajithkumar, Thalasseril Govindankuttykaimal and Hossain, Munshi Sahid and Bandyopadhyay, Subhajit and Kundu, Subrata and Banerjee, Rahul}
}
@article {49056,
	title = {Water-chain mediated proton conductivity in mechanically flexible redox-active organic single crystals},
	journal = {Journal of Materials Chemistry A},
	volume = {12},
	year = {2024},
	month = {MAR },
	pages = {5866-5874},
	type = {Article},
	abstract = {<p>
	Investigating electrochemical features of proton-conducting organic crystalline materials is relevant in developing efficient energy storage and conversion devices. However, the poor structural flexibility of the crystalline materials at the molecular level often impedes hydrogen bond reorganization of the proton carriers during proton migration, ultimately leading to low ionic conductivity. Here, we report crystals of azobenzene, functionalized with dipicolylamine at both ends (Azo-DPA), which contain an extended hydrogen-bonding network with water molecules in its structure. Interestingly, the crystals display remarkable mechanical flexibility explicitly probed by the nanoindentation technique. The mechanically flexible neutral organic crystals devoid of any acidic moieties (-COOH, -PO3H2, etc.) within the system, exhibit promising proton conductivity (1.63 x 10-4 S cm-1 at 30 degrees C under 95\% relative humidity) which is almost 100 times better compared to the neutral organic systems reported to date. Mechanically flexible redox-active crystalline organic material (Azo-DPA) capable of impressive proton conduction was employed as an electrode material for the first time in an aqueous battery containing Zn2+ ions. The experimental and theoretical studies on the charge storage mechanism revealed the redox activity of the azo (-N 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 N-) centers involving reversible insertion/extraction of protons and Zn2+ ions. Ultimately, the electrode displayed a specific capacity similar to 49 mA h g-1 with almost 100\% retention after 1400 cycles, encouraging the scope of redox-active organic crystalline materials for energy storage applications. Investigating the electrochemical features of proton-conducting flexible organic crystalline materials is crucial for the development of efficient energy storage and conversion devices.</p>
},
	issn = {2050-7488},
	doi = {10.1039/d3ta05797f},
	author = {Hossain, Munshi Sahid and Ghosh, Meena and Mondal, Amit and Ajmal, P. and Saha, Monochura and Reddy, C. Malla and Kurungot, Sreekumar and Bandyopadhyay, Subhajit}
}
