The role of WO_x species as a shape-control agent in TiO₂-WO₃ heterojunctions for hydrogen photocatalytic production

The engineering of crystal facets using tungsten oxide as a shape-control agent was used to enhance the TiO₂ photocatalytic activity. TiO₂-WO₃ heterojunctions with well-dispersed WO_x nanostructures and co-exposed {001} and {010} facets were obtained without calcination treatment. This procedure effectively ensures the contact between both oxides and the optimal contact allows the control shape of TiO₂ to ensure photogenerated charge separation and improve the photocatalytic activity of TiO₂-WO₃ heterojunctions. The addition of WO_x clusters to the TiO₂ was beneficial to the formation of surface oxygen vacancies and the synergistic effect of oxygen vacancies with the optimal proportion of the oxidative {001} to the reductive {101} facets, improved the photocatalytic hydrogen production and the degradation of methyl orange. These findings have significant implications for developing more efficient and sustainable photocatalytic systems.