Remarkable Improvement in Water Oxidation Catalysis by Moderate Heat Treatment of a Crystalline Silver-Based Thin Film Developed In-Situ From Silver-ions in Acetate Solution

摘要

Water oxidation is an important half-reaction to achieve overall water splitting. Therefore, the development of efficient electrocatalysts for water oxidation is an avenue to improve the competence of fuel generation technology. In this study, a crystalline silver-based film (AgxO), electrodeposited in-situ on FTO electrodes from a sodium acetate solution containing silver ions at pH ~6, shows a remarkable improvement in the water oxidation catalysis after heat treatment at moderate temperature (100 ℃). The morphology, nature and composition of the thin films were fully characterized by scanning electron microscopy, atomic force microscopy, powder X-ray diffraction, X-ray photoelectron and energy dispersive X-ray spectroscopies. The electrode, annealed at 100 ℃, generates a sustain current density ~2.25 mA cm~(-2) for at least 12 h, which is almost two order of magnitude larger than the as-deposited electrode in a sodium borate buffer solution of pH 9.2.