IrO2 shell–Ir−Ni core particulate films (denoted
as IrO2 (Ir−Ni)) have been prepared by galvanic
replacement of Ni layers electrodeposited on glassy carbon (GC) electrodes.
The method involves three steps: immersion of the Ni/GC electrode
into a deaerated solution of Ir(IV) at 65 °C for 15 min (galvanic
replacement); electrochemical treatment of the resulting Ir−Ni/GC
electrode for anodic dissolution of nonreacted surface Ni and surface
enrichment in Ir (formation of a precursor core–shell structure
denoted as Ir (Ir−Ni)); anodization of the resulting Ir (Ir−Ni)/GC
system (iridium dioxide formation). The resulting IrO2 (Ir−Ni)/GC
electrodes have been characterized by SEM/EDS, AFM, and XPS, revealing
a particulate morphology (submicron particles), an Ir-rich bulk atomic
composition (Ir/Ni atomic ratio of ca. 5), and a thin IrO2 shell. Electrochemical characterization in acid solutions in both
the H adsorption/desorption and the oxide formation/reduction potential
ranges points to complete surface coverage by IrO2. The
prepared IrO2 (Ir−Ni)/GC electrodes have been tested
as anodes for oxygen evolution (OER) from acid solutions by means
of EIS and steady-state current–potential plots; they have
been proven to exhibit superior intrinsic catalytic activity for OER
compared to that of plain IrO2 anodically grown on bulk
Ir.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.