sAJM589

In aqueous organic redox flow batteries (AORFBs), the inherent problems, such as low energy and poor chem. stability, remain obstacles to the growth of AORFBs for the large-scale energy storage system (ESS).To address these challenges, this paper describes a novel benzo[a]phenazin-5-ol methanesulfonate (BHPS, C₁₆H₁₀N₂O₄S) containing sulfonic acid and hydroxyl functional groups, which undergoes a highly stable and reversible two-electron redox reaction in aqueous media, and allows high chem. stability, superb conductivity, high redox potential (-0.943 V) and excellent solubilityThe superior chem. and electrochem. properties of the proposed BHPS are demonstrated through various experiments, including full cell-cycling tests, along with theor. mol. anal.Exptl. results show that the BHPS with highly conductive sulfonic acid group (along with hydroxyl group) leads to 1.83 times higher kinetic constant (1.32 x 10^-3 cm s^- 1) and 98.07 times higher solubility (1.47 M) than the benzo[a]phenazine-5-ol (HBP, C₁₆H₁₀N₂O).Further, the BHPS/Fe(CN)₆ flow-cell cycling for 100 cycles at 60 mA cm^-2 results in great coulombic and energy efficiencies of average 99.5 and 81.9%, along with dramatic charge-and-discharge capacity retention ratios of average 99.79 and 99.25% with initial charge and discharge capacities of 49.11 and 48.76 mAh, resp.The BHPS successfully synthesized by the attachment of the sulfonic acid and hydroxyl groups to benzo[a]phenazine provides a promising anodic organic species for highly efficient AORFBs, and its performance can be further optimized by mol. engineering.

In the present study, a nano-metal organic framework (MOF) based on copper was synthesized and characterized by various techniques, such as SEM (SEM), powder X-ray diffraction (pXRD), thermogravimetric anal. (TGA), Fourier transform IR (FT-IR) and N₂ adsorption/desorption isotherms.The Cu-benzene dicarboxylic acid (Cu-BDC) exhibited high catalytic activity under ultrasonic irradiation for one-pot synthesis benzophenazine using 2-hydroxy-1,4-naphthoquinone, o-phenylenediamine, aldehydes, and malononitrile as the starting material.Cu-BDC as a heterogeneous catalyst in the synthesis of benzophenazines can be reused and recycled several times by maintaining its catalytic activities.