Developing nonprecious metal-based electrocatalysts to convert water into green fuels (H2 and O2) is key to address urgent climate and energy challenges. We have prepared an electrocatalyst by the immobilization of NiCo2O4 on a phosphazene-based covalent organic polymer (P-COP) through a facile hydrothermal method. The elemental composition of the P-COP showed the presence of a greater amount of heteroatoms N (6.62%) and P (5.62%) throughout the polymer support. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were utilized to determine the atomic structure of the nanocuboids, which depicted the formation of an inverse spinel structure. A NiCo2O4-P-COP-based electrode was simultaneously used for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), and it displayed a minimum overpotential of 270 and 130 mV (V vs RHE), respectively, at a current density of 10 mA cm–2. In addition, it acted as an oxygen reduction catalyst with a half-wave potential of 0.83 V (V vs RHE) and a maximum current density of 4.5 mA cm–2. The electrocatalytic activity is comparable with that of the commercially available Pt and RuO2 catalysts. The combined experimental and computational studies confirm that the catalytic centers formed through the interaction between the heteroatoms (N and P) in the phosphazene matrix and metal oxides (Co and Ni) play an important role in its improved durability and electrocatalytic activity.

A simple green protocol for the synthesis of 3-aminochromone derivatives using a NHC catalyzed intramolecular hydroacylation reaction was developed. Further functional 3-aminochromes were evaluated for their anticancer activity.

Organic−inorganic hybrid polymeric materials have shown potential applications in various fields. An approach to prepare a new class of a covalent organic−inorganic hybrid polymer (COIHP-1) using tris (2,3,6,7,10,11-hexahydroxytriphenylene) and inorganic heterocycle (hexachlorophosphazene) is developed. The design of COIHP-1 with porous nature has been an important goal as it can fulfill the demands of next-generation batteries and other electrochemical devices. COIHP-1 shows a high electrical conductivity of 9.52 × 10 −3 S/cm. For the first time, COIHP-1 is employed as an anode material with maximum capacity in Na + batteries, and it was characterized by various spectroscopic studies. It delivers a reversible capacity of 310 mAh g −1 at a current density of 0.035 A g −1 , retains 65% of initial capacity after 500 cycles, and preserves the mesoporous nature even after prolonged cycling as proved by the post transmission electron microscopy (TEM) analysis. Moreover, COIHP-1 shows an excellent rate capability: it delivers 90 mAh g −1 even at a high current density of 3 A g −1 . The enhanced Na + storage capability, cycling stability, and rate capability are due to the mesoporous scaffold, which offers reversible accommodation for the ions. Mainly, the Na + storage capability of COIHP-1 arises because of its polymeric −PN− framework layer, which also provides hosting sites for the ions in the π-bond or lone pair of N. This work opens a door for developing a new kind of hybrid polymeric electrode material for rechargeable Na + batteries.

A simple protocol for the synthesis of the dihydropyran core structure of secoiridoids using NHC catalyzed Coates-Claisen rearrangement is described.

A simple and efficient direct radical C-2 arylation of 3-aminochromone derivatives with aryl hydrazine is described. The aryl hydrazine acts as an initiator and source for aryl radical via cleavage...