Mechanistic insights into photogenerated electrons store-and-discharge in hydrogenated glucose template synthesized Pt: TiO2/WO3 photocatalyst for the round-the-clock decomposition of methanol

Abstract

This study demonstrates the glucose-template assisted synthesis of hydrogen-treated Pt: TiO2/WO3 composites, and their round-the-clock photoactivity towards methanol (MeOH) degradation under light illumination and in dark. XRD indicated increasing rutile fraction in TiO2 as a function of template removal, WO3 crystallinity and H2 treatment process. The presence of oxygen vacancies in WO3 was confirmed by XPS. Lower recombination rate and higher surface area were observed in the optimized H2-Pt-G:TiO2/WO3 catalyst. The presence of oxygen vacancies and optical enhancements due to the synergistic interactions of the multi-system (TiO2, WO3 and Pt) extended the visible light absorption of the system, increasing photocatalytic activity, with 61 % of MeOH degradation in 2 h of irradiation and 33 % in dark in 6 h. The origin of the observed efficiency was further validated using photo-electrochemical investigations, which revealed appropriate interfacial contacts in Pt: TiO2/WO3 system, maximum charge separation and charge transfer thanks to oxygen vacancies.