Photoinduced Glycerol Oxidation over Plasmonic Au and AuM (M = Pt, Pd and Bi) Nanoparticle-Decorated TiO(2) Photocatalysts

In this study, sol-immobilization was used to prepare gold nanoparticle (Au NP)-decorated titanium dioxide (TiO(2)) photocatalysts at different Au weight % (wt. %) loading (Au(x)/TiO(2), where x is the Au wt. %) and Au–M NP-decorated TiO(2) photocatalysts (Au(3)M(3)/TiO(2)), where M is bismuth (Bi), platinum (Pt) or palladium (Pd) at 3 wt. %. The Au(x)/TiO(2) photocatalysts exhibited a stronger visible light absorption than the parent TiO(2) due to the localized surface plasmon resonance effect. Increasing the Au content from 1 wt. % to 7 wt. % led to increased visible light absorption due to the increasing presence of defective structures that were capable of enhancing the photocatalytic activity of the as-prepared catalyst. The addition of Pt and Pd coupled with the Au(3)/TiO(2) to form Au(3)M(3)/TiO(2) improved the photocatalytic activity of the Au(3)/TiO(2) photocatalyst by maximizing their light-absorption property. The Au(3)/TiO(2), Au(3)Pt(3)/TiO(2) and Au(3)Pd(3)/TiO(2) photocatalysts promoted the formation of glyceraldehyde from glycerol as the principle product, while Au(3)Bi(3)/TiO(2) facilitated glycolaldehyde formation as the major product. Among all the prepared photocatalysts, Au(3)Pd(3)/TiO(2) exhibited the highest photocatalytic activity with a 98.75% glycerol conversion at 24 h of reaction time.