Tailored Nanoparticle Organic Network Membranes for Hydrogen Generation

Assembling metal nanoparticles (MNPs) into extended structures is an emerging area of research for designing metamaterials. Conventional strategies for MNP assembly are primarily driven by noncovalent interactions, often resulting in trade-offs between structural integrity and ease of processability. In this direction, nanoparticle organic network membranes (NONM) are developed using a unique covalent chemistry-inspired liquid-liquid (L/L) interfacial approach. The NONM fabrication has been achieved in two consecutive steps. In the first step, functionalized silver nanoparticles (AgNPs) are covalently anchored to free formyl groups of pre-mature covalent organic framework membranes (COFMs) - to suppress the agglomeration of AgNPs, and in the second step, further covalent connections are established with dialdehydic linkers, resulting in free-standing NONMs (AgNONMs). Capitalizing on the electrocatalytic activity of AgNPs and the enhanced charge transfer, the AgNONMs pose potential as ready-to-use membrane electrodes for electrochemical hydrogen evolution reaction (HER). HER finding of AgNONMs shows a higher current density and lower overpotential compared to the pristine COFMs. Furthermore, a unique approach of assembling MNPs in a processable form will inspire the development of the next generation NON membranes for electrocatalytic and optoelectronic applications.