Iron vs Aluminum Based Layered Double Hydroxides as Water Splitting Catalysts

Abstract

This paper describes the electrosynthesis, characterization and electrocatalytic properties towards oxygen evolution reaction (OER) of four layered double hydroxides (LDHs) containing cobalt or nickel as divalent cation and aluminum or iron as trivalent metal. The electrochemical behaviour of the LDH modified electrodes was studied by cyclic voltammetry (CV), and the LDHs were characterized by XRD and SEM/EDS. Two materials, i.e., platinum and glassy carbon (GC), were investigated as electrode supports recording polarization and chronopotentiometric curves, with a rotating disk electrode in alkaline solutions. LDHs containing iron exhibited higher activity for OER and all the materials showed a good stability and durability in alkaline media. When GC was used as electrode support the performances of the OER catalysts resulted to be even better than those exhibited by the same LDHs electrodeposited on Pt.