Suberic Acid-Modified Y-Co(OH)₂ Nanosheets with Cationic Vacancies for Efficient Oxygen Evolution Reaction

Abstract

Two-dimensional metal oxides/hydroxides are considered to be promising to drive the oxygen evolution reaction (OER). In this work, Y-doped Co(OH) 2 nanosheets modified with deficient suberic acid (DSA-Y-Co(OH) 2 ) were synthesized by a one-step hydrothermal method. The DSA-Y 0.05 -Co(OH) 2 catalyst (the molar ratio of Y to Co is 0.05) exhibits excellent OER performance in alkaline solution, at 10 mA cm −2 , with much lower overpotential (311 mV) than that of the commercial catalyst IrO 2 (347 mV). The superior performance results from the increase of active sites by Y doping (Y-doping-induced cationic vacancies) and the surface modification of suberic acid (SA) molecules promoting the accessibility of active sites. Theoretical calculations confirm that the combined effect of Y doping and surface functionalization of SA improved the OH − adsorption kinetics (a rate-determining step inferred by Tafel). This work guides the application of heteroatom doping and organic molecular surface functionalization strategies in catalysis.

Defect engineering: the role of cationic vacancies in photocatalysis and electrocatalysis

“…Examples include doping, chemical reduction, electrochemical exfoliation and heat treatment. Jing et al 38 synthesized Y-doped hexagonal Co(OH) 2 (DSA-Y 0.05 -Co(OH) 2 ) catalysts through surface functionalization with suberic acid and a Y-doping strategy. In the neutralization reaction between acid and base at room temperature, Co(OH) 2 is generated, while the introduction of suberic acid results in coordination with certain Co ions.…”