Plasma Treatment as a Promising Environmentally Benign Approach for Synthesis of Valuable Multi-gas Doped Nano-TiO₂...

An ingenious prospect has been established to synthesize a wide range of non-metal-doped TiO₂ -P25 by plasma technique. Different atmospheres (Air, O₂ , N₂ , Ar and CO₂ ) have been embedded on the surface of TiO₂ -P25 by plasma treating as an effective alternative to wet chemical pretreatment processes. This approach is clean beyond recognition by employing pure gases as well as no need to poison precursors or organic solvents without producing waste stream, which surprisingly can meet green chemistry purposes. More specifically, plasma has been a contributing factor in the narrowing band gap energies of doped photocatalysts in comparison with pure TiO₂ -P25. Synthesized photocatalysts gained enormous benefit from the plasma treatment in the selective oxidation of benzyl alcohols to associating aldehydes under blue LED illumination with excellent yields, which dramatically decreased the time reaction to many folds. Additionally, benzaldehyde formation under influence of various wavelengths of visible light, including blue photons (λ_max = 460 nm), green photons (λ_max = 510 nm) and red photons (λ_max = 630 nm) was compared to assess the effect of plasma treating on photoactivity of nano-TiO₂ -P25. Furthermore, as-prepared photocatalysts were investigated by diverse characterization techniques.