Au − Pd/mesoporous Fe2O3: Highly active photocatalysts for the visible-light-driven degradation of acetone.

Three-dimensionally ordered mesoporous Fe 2 O 3 (meso-Fe 2 O 3 ) and its supported Au, Pd, and Au − Pd alloy ( x AuPd y /meso-Fe 2 O 3 ; x = 0.08–0.72 wt.%; Pd/Au molar ratio ( y ) = 1.48–1.85) photocatalysts have been prepared via the KIT-6-templating and polyvinyl alcohol-protected reduction routes, respectively. Physical properties of the samples were characterized, and their photocatalytic activities were evaluated for the photocatalytic oxidation of acetone in the presence of a small amount of H 2 O 2 under visible-light illumination. It was found that the meso-Fe 2 O 3 was rhombohedral in crystal structure. The as-obtained samples displayed a high surface area of 111.0–140.8 m 2 /g and a bandgap energy of 1.98–2.12 eV. The Au, Pd and/or Au–Pd alloy nanoparticles (NPs) with a size of 3–4 nm were uniformly dispersed on the surface of the meso-Fe 2 O 3 support. The 0.72 wt.% AuPd 1.48 /meso-Fe 2 O 3 sample performed the best in the presence of 0.06 mol/L H 2 O 2 aqueous solution, showing a 100% acetone conversion within 4 hr of visible-light illumination. It was concluded that the good performance of 0.72 wt.% AuPd 1.48 /meso-Fe 2 O 3 for photocatalytic acetone oxidation was associated with its ordered mesoporous structure, high adsorbed oxygen species concentration, plasmonic resonance effect between AuPd 1.48 NPs and meso-Fe 2 O 3 , and effective separation of the photogenerated charge carriers. In addition, the introduction of H 2 O 2 and the involvement of the photo-Fenton process also played important roles in enhancing the photocatalytic activity of 0.72 wt.% AuPd 1.48 /meso-Fe 2 O 3 . [ABSTRACT FROM AUTHOR]