A robust iron oxyhydroxide water oxidation catalyst operating under near neutral and alkaline conditions

Abstract

Efficient electrochemical splitting of water to hydrogen and oxygen using cheap and abundant metal ion based catalysts is of fundamental significance to solar devices. For an efficient water splitting reaction, the development of a highly active, robust and cost-effective catalyst is desirable. Herein, we report iron oxyhydroxide thin films as an efficient water oxidation catalyst. The films have been electrochemically deposited applying anodic potential in the presence of a nonaqueous solvent, using ferrocene as the metal ion precursor and exclude interference from the problems of precipitation of iron hydroxide during the deposition process. The as-prepared films exhibit high catalytic activity towards the oxygen evolution reaction under alkaline as well as under near neutral conditions. Long term testing results showed that the films were able to oxidize water for almost 8 h of continuous operation with a current density of 10 mA cm⁻² at an overpotential of 600 mV under near neutral conditions. The facile method of electrodeposition reported here with outstanding catalytic efficiency is of great significance for the large scale production of hydrogen.