Amphoteric Membrane Loaded with a Noble Metal-Free Hollow Spherical NiCoP@rGO Bifunctional Electrocatalyst for Alkaline Water Electrolyzers

For overall water splitting and simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) processes in alkaline media, a bifunctional electrocatalyst loaded on both surfaces of an amphoteric ion exchange membrane (AIEM) was conceptualized to improve the efficiency. Herein, we report a partially lene))-based AIEM grafted with sulfonic acid and quaternary amine functional groups. The prepared AIEM was utilized as a substrate for the loading of the electrocatalyst (hollow spherical NiCoP@rGO) to prepare a membrane electrode assembly. The morphology-dependent bifunctional performance of the NiCoP@rGO electrocatalyst was assessed for overall water splitting (HER and OER). The prepared electrocatalyst exhibited a low potential (0.297 V for the HER and 1.57 V for the OER) at 10.00 mA/cm2 current density, corresponding to 129 and 110 mV/dec Tafel slopes, respectively. Thus, the prepared MEA exhibited better overall water splitting performance in comparison to other commercialized membrane substrates and reported electrocatalysts in the literature, at 30 degrees C under 400 mA/cm2 in alkaline medium (1.0 M KOH). A stable fluorinated polymer-based AIEM and hollow spherical NiCoP@rGO electrocatalyst provide a significant improvement in water electrolysis and simultaneous H2 and O2 production via HER and OER processes.

Automated summary

A bifunctional electrocatalyst loaded on an amphoteric ion exchange membrane was developed for efficient water splitting and simultaneous HER and OER processes in alkaline media. The prepared membrane electrode assembly exhibited better overall water splitting performance compared to other commercialized membrane substrates and reported electrocatalysts.