The Effect of the Reducing Sugars in the Synthesis of Visible-Light-Active Copper(I) Oxide Photocatalyst

Photoinhibitive Properties of α-MoO3 on Its Composites with TiO2, ZnO, BiOI, AgBr, and Cu2O

Orthorhombic molybdenum trioxide (α-MoO₃) is well known as a photocatalyst, adsorbent, and inhibitor during methyl orange photocatalytic degradation via TiO₂. Therefore, besides the latter, other active photocatalysts, such as AgBr, ZnO, BiOI, and Cu₂O, were assessed via the degradation of methyl orange and phenol in the presence of α-MoO₃ using UV-A- and visible-light irradiation. Even though α-MoO₃ could be used as a visible-light-driven photocatalyst, our results demonstrated that its presence in the reaction medium strongly inhibits the photocatalytic activity of TiO₂, BiOI, Cu₂O, and ZnO, while only the activity AgBr is not affected. Therefore, α-MoO₃ might be an effective and stable inhibitor for photocatalytic processes to evaluate the newly explored photocatalysts. Quenching the photocatalytic reactions can offer information about the reaction mechanism. Moreover, the absence of photocatalytic inhibition suggests that besides photocatalytic processes, parallel reactions take place.