Photocatalysis and photoelectrochemical glucose oxidation on Bi2WO6: Conditions for the concomitant H2 production

Glucose solar light photoinduced oxidation on Bi2WO6 and the chemical kinetics conditions for concurrent photoelectrochemical H-2 production are reported. The results show that the conversion of this organic compound is determined by their surface concentration according to the Langmuir-Hinshelwood mechanism. The performance of Bi2WO6 powder for the photocatalytic oxidation of glucose is higher than that observed with TiO2-based materials. Glucose degradation and mineralization rates are similar; therefore, stable intermediates are not formed during glucose oxidation. Photoluminescence studies indicate that glucose promotes electron injection into the valence band of semiconductor. The initial glucose concentration in combination with the electrode potential used, determines the H-2 production. In fact, electrode potential of 0.9 V vs. SHE and 60 ppm of glucose defines kobs values equal to kK with maximum H-2 evolution rate: 3.05 mmol h(-1) cm(-2). This value arises from the transformation of the 97% of the Faradaic current measured. The phenomenological conditions for renewable energy applications have been envisaged. (c) 2020 Elsevier Ltd. All rights reserved.