Au − Pd/mesoporous Fe2O3: Highly active photocatalysts for the visible-light-driven degradation of acetone
Hongxia Lin , Yuxi Liu , Jiguang Deng , Kunfeng Zhang , Xing Zhang , Shaohua Xie , Xingtian Zhao , Jun Yang , Zhuo Han , Hongxing Dai
DOI:10.1016/j.jes.2017.11.013
Received June 19, 2017,Revised , Accepted November 10, 2017, Available online November 16, 2017
Volume 30,2018,Pages 74-86
Three-dimensionally ordered mesoporous Fe2O3 (meso-Fe2O3) and its supported Au, Pd, and Au − Pd alloy (xAuPdy/meso-Fe2O3; 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 H2O2 under visible-light illumination. It was found that the meso-Fe2O3 was rhombohedral in crystal structure. The as-obtained samples displayed a high surface area of 111.0–140.8 m2/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-Fe2O3 support. The 0.72 wt.% AuPd1.48/meso-Fe2O3 sample performed the best in the presence of 0.06 mol/L H2O2 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.% AuPd1.48/meso-Fe2O3 for photocatalytic acetone oxidation was associated with its ordered mesoporous structure, high adsorbed oxygen species concentration, plasmonic resonance effect between AuPd1.48 NPs and meso-Fe2O3, and effective separation of the photogenerated charge carriers. In addition, the introduction of H2O2 and the involvement of the photo-Fenton process also played important roles in enhancing the photocatalytic activity of 0.72 wt.% AuPd1.48/meso-Fe2O3.
