Titania modification with a ruthenium(ii) complex and gold nanoparticles for photocatalytic degradation of organic compounds. Issue 1 (14th December 2015)

• Record Type: Journal Article
• Authors: Zheng, Shuaizhi; Wei, Zhishun; Yoshiiri, Kenta; Braumüller, Markus; Ohtani, Bunsho; Rau, Sven; Kowalska, Ewa
• Is Part Of: Photochemical & photobiological sciences. Volume 15:Issue 1(2016:Jan.)
• Page Start: 69
• Page End: 79
• Publication Date: 2015-12-14
• Subjects: Photochemistry -- Periodicals; Photobiology -- Periodicals; 541.35
• DOI: 10.1039/c5pp00345h
• Languages: English
• ISSNs: 1474-905X

Abstract

Abstract : Interaction between two kinds of titania modifiers, i.e., a ruthenium complex and gold nanoparticles, influenced the resultant properties and photocatalytic activities of hybrid photocatalysts under UV and/or vis light irradiation. Abstract : Titania of fine anatase nanoparticles (ST01) was modified successively with two components, i.e., a ruthenium(ii ) complex with phosphonic anchoring groups [Ru(bpy)2 (4, 4′-(CH2 PO3 H2 )2 bpy)] 2+ bpy = 2, 2′-bipyridine (Ru II CP) and gold nanoparticles (Au). Various compositions of two titania modifiers were investigated, i.e., Au, Au + Ru II CP, Au + 0.5Ru II CP, Ru II CP, 0.5Ru II CP and 0.25Ru II CP, where Au and Ru II CP correspond to 0.81 mol% and 0.34 mol% (with respect to titania), respectively. In the case of hybrid photocatalysts, the sequence of modification (ruthenium(ii ) complex adsorption or gold deposition) was investigated to check its influence on the resultant properties and thus photocatalytic performance. Diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) were applied to characterize the structural properties of the prepared photocatalysts, which confirmed the successful introduction of modifiers of the ruthenium(ii ) complex and/or gold NPs. Different distributions of gold particle sizes and chemical compositions were obtained for the hybrid photocatalysts prepared with an opposite sequence. It was found that photocatalytic activities depended on the range of used irradiation (UV/vis or vis) and the kind of modifier in different ways. Gold NPs improved the photocatalytic activities, while Ru II CP inhibited the reactions under UV/vis irradiation, i.e., methanol dehydrogenation and acetic acid degradation. Oppositely, Ru II CP greatly enhanced the photocatalytic activities for 2-propanol oxidation under visible light irradiation.