| 摘 要： | Three-dimensionally ordered mesoporous Fe_2O_3(meso-Fe_2O_3) and its supported Au, Pd,and Au-Pd alloy(xA uP dy/meso-Fe_2O_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_2O_2 under visible-light illumination. It was found that the meso-Fe_2O_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_2O_3 support. The 0.72 wt.% AuP d1.48/meso-Fe_2O_3 sample performed the best in the presence of 0.06 mol/L H_2O_2 aqueous solution, showing a 100% acetone conversion within4 hr of visible-light illumination. It was concluded that the good performance of 0.72 wt.%AuPd_(1.48)/meso-Fe_2O_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_2O_3, and effective separation of the photogenerated charge carriers. In addition, the introduction of H_2O_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_2O_3.
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