Water oxidation photocatalysis : Mn-based co-catalysts on TaON

Abstract

TaON was studied as a photocatalytic material for visible light driven water oxidation. Anomalies in the structure of the material such as lattice strain or oxygen deficiencies were shown to have a negative influence on its photocatalytic activity, as defects act as recombination centers for the photogenerated charge carriers. TaON was loaded with a manganese-based co-catalyst to enhance its activity. Mn deposition was realized following two procedures: deposition-precipitation and impregnation. The loading procedure was shown to have a great influence on the morphology and dispersion of the co-catalyst and therefore on its activity. Having showed more promising results, we deepened our investigations on the deposition-precipitation procedure and studied the influence of the pH-control agent on the morphology of the sample. To measure electrochemical and photocatalytical OER-activity we adapted to our system two testing methods based on the use of two sacrificial agents: the CAN test and the Ag test