Effect of Light and Electrode Polarization on BiVO4 and TiO2 Photoanodes for Glycerol Oxidation

Abstract

In recent years, there has been a growing interest in the photoelectrochemical oxidation of glycerol to produce high-value products. Most studies have focused solely on the photocatalytic properties of the electrodes, overlooking their electrocatalytic properties and the different products obtained under dark conditions. Our work aims to address this gap by comparing the electrocatalytic activity under dark and light conditions to determine whether light influences the reactivity of the electrodes or if it just reduces the overpotential of the reaction. To achieve this, we employed two model semiconductors, TiO2 and BiVO4. We have analyzed their polarization curves under both dark and light conditions and evaluated the competence of glycerol oxidation reaction with the oxygen evolution reaction. Furthermore, we conducted long-term (photo)electrolysis revealing the beneficial role of light on the electrolytic process, as it enables the obtention of C3 products on illuminated TiO2 photoanodes at low electrode polarization, comparable to the performance of BiVO4.