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The carbohydrazide-based gelation component N2,N4,N6-(1,3,5-triazine-2,4,6-triyl)tris(benzene-1,3,5-tricarbohydrazide) (CBTC) was synthesized and characterized using various spectroscopic tools. CBTCand trimesic acid (TMA) get self-assembled to form metallogel with Fe3+, specifically through various noncovalent interactions in a DMSO and H2O mixture. The self-assembly shows remarkable specificity toward Fe(III) among different transition metal salts. It is pertinent to point out that the binding specificity for Fe3+can also be found in nature in the form of siderophores, as they are mainly involved in scavenging iron selectively from the surroundings. DFT studies have been used to investigate the possible interaction between the different components of the iron metallogel. To determine the selectivity of CBTCfor iron, CBTC, along with trimesic acid, is used to interact with other metal ions, including Fe(III) ions, in a single system. The gelation components CBTCand TMAselectively bind with iron(III), which leads to the formation of metallogel and gets separated as a discrete layer, leaving the other metal ions in the solution. Therefore, CBTCand TMAtogether show iron-scavenging properties. This selective scavenging property is explored through FE-SEM, XPS, PXRD, IR, and ICP-AES analysis. The FE-SEM analysis shows a flower-petal-like morphology for the Fe(III) metallogel. The resemblance in the CBTC-TMA-Femetallogel and metallogel obtained from the mixture of different metal salts is established through FE-SEM images and XPS analysis. The release of iron from the metallogel is achieved with the help of ascorbic acid, which converts Fe3+to Fe2+. In biological systems, iron also gets released similarly from siderophores. This is the first report where the synthesized gelation component CBTCmolecule is capable of scavenging out iron in the form of metallogel and self-separating from the aqueous mixture in the presence of various other metal ions.

Hydrogen peroxide, an environmentally friendly oxidant, is in high demand in various industrial sectors. Electrochemical H2O2production by 2e–reduction of O2is a suitable and greener alternative to the traditional anthraquinone process. However, developing metal-free electrocatalysts that predominantly follow the 2e–reduction process over the more favorable 4e–reduction is challenging. Here, we report a viologen-based redox-active ionic porous organic polymer (iPOP-TAPA-Cl) toward selective production of H2O2(86%) electrocatalytically. By varying the counteranion (Cl–) with other halogen anions (F–, Br–, and I–), a maximum H2O2selectivity of 98.5% with exceptional current efficiency was achieved in the case of iPOP-TAPA-F.