Prussian blue analog-derived nickel iron phosphide-reduced graphene oxide hybrid as an efficient catalyst for overall water electrolysis

Efficient and bifunctional nonprecious catalysts for oxygen evolution reaction (OER) and hydrogen evo-lution reaction (HER) are essential for the production of green hydrogen via water electrolysis. Transition metal (Ni, Co, Fe, etc.) phosphides are frequently documented HER catalysts, whereas their bimetallic oxi-des are efficient OER catalysts, thus enabling bifunctional catalysis for water electrolysis via proper oper-ation. Herein, phosphide-reduced graphene oxide (rGO) hybrids were prepared from graphene oxide (GO)-incorporated bimetal Prussian blue analog (PBA) precursors. The hybrids could experience partial surface oxidation to create oxide layers with OER activities, and the hybrids also possessed considerable HER properties, therefore enabling bifunctional catalytic features for water electrolysis. The typical NiFeP-rGO hybrid demonstrated an overpotential of 250 mV at 10 mA cm-2 and good durability for OER, as well as moderate HER catalytic features (overpotential of 165 mV at-10 mA cm-2 and acceptable catalytic stability). Due to the bifunctional catalytic features, the NiFeP-rGO-based symmetric water elec-trolyzer demonstrated a moderate input voltage and high faradaic efficiency (FE) for O2 and H2 produc-tion. The current work provides a feasible way to prepare OER and HER bifunctional catalysts by facile phosphorization of PBA-associated precursors and spontaneous surface oxidation. Given the oxidation/ reduction bifunctional catalytic behaviors, phosphide-rGO hybrid catalysts have great potential for wide-spread application in fields beyond water electrolysis, such as electrochemical pollution abatement, sen-sors, energy devices and organic syntheses.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

Efficient and bifunctional phosphide-reduced graphene oxide (rGO) hybrid catalysts were used for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), enabling the production of green hydrogen through water electrolysis.