Enhancement of the electrochemical oxygen evolution reaction by light and external magnetic fields, using hybrid electrodes made by Langmuir–Blodgett

Abstract

The implementation of water electrolysis technology is hampered by the slow kinetics of the oxygen evolution reaction. In an attempt to solve this issue, anodes which are able to respond to external stimuli such as magnetic field and light were successfully prepared by the Langmuir-Blodgett technique, using Fe3O4 magnetic nanoparticles (FTO/Fe3O4) and Fe3O4 nanoparticles together with tetrathiafulvalene as photosensitizer (FTO/Fe3O4/TTF).This technique allowed obtaining highly stable and homogeneous anodes in a simple and reproducible way. The electrodes produced a catalytic effect on the water oxidation reaction, without the use of a noble-metal, and proved to be sensitive to a 365 nm LED light as well as to an external magnetic field. Water oxidation reaction was evaluated by linear sweep voltammetry, by the Tafel slopes and also by electrochemical impedance spectroscopy. This work presents new perspectives for the water oxidation reaction, using electrodes fabricated by the Langmuir-Blodgett technique and catalyzed through the use of external stimuli such as light and magnetic fields.