Pt–Ru Bimetal Alloy Loaded TiO2 Photocatalyst and Its Enhanced Photocatalytic Performance for CO Oxidation

• Published in: Journal of physical chemistry. C 2016-05, Vol.120 (18), p.9732-9739
• Main Authors: Zhang, Tingting, Wang, Shuting, Chen, Feng
• Format: Article
• Language: English
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.5b12251

Pt–Ru alloy loaded TiO2 (RP-AH) photocatalyst with superior photocatalytic performances was prepared in this work. First, RuO2/TiO2/Pt ternary photocatalyst (RP) is calcined in air to epitaxially spread RuO2 nanoclusters on the surface of TiO2 (RP-A), which ensures the close contact of RuO2 with the Pt nanoparticles nearby. Then, RuO2 is reduced into metallic Ru to form Pt–Ru alloy via calcining in a H2 atmosphere. XRD, TEM, XPS, and CV are applied to verify the formation of Pt–Ru alloy nanoparticles, while the photocurrent and Mott–Schottky plots suggest that RP-AH is a p-type semiconductor. The RP-AH catalyst shows a superior photocatalytic activity to those of RP, RP-A, and RP-H (Ru/TiO2/Pt) in CO oxidation under UV irradiation. CO of a concentration of 1000 ppm was completely photocatalytically oxidized into CO2 with RP-AH in 120 min. Either Pt–Ru alloy or p-type semiconductor property of RP-AH plays an effective role in improving the photocatalytic performance of RP-AH. Academically, Pt–Ru alloy clusters favor the adsorption of CO and O2 as well as promote the separation of the photogenerated charges in RP-AH; meanwhile, the high hole mobility due to the p-type semiconductor property of RP-AH also benefits the reactivity of holes in oxidizing CO into CO2 with O– (a).