Enhanced photocatalytic activity of TiO2 nanotubes arrays decorated with Ag and Pt nanoparticles. (2022)

• Record Type: Journal Article
• Authors: Tamilselvan, A.; Durgalakshmi, D.; Ajay Rakkesh, R.; Balakumar, S.
• Is Part Of: Materials today. Volume 64:Part 5(2022)
• Page Start: 1822
• Page End: 1831
• Publication Date: 2022
• Subjects: Ag/TiO2 nanotubes -- Pt/TiO2 nanotubes -- Photocatalyst -- Schottky barrier -- Recombination rate; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2022.06.135
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: In this work, vertically aligned TiO2 nanotubes arrays have been synthesized by the electrochemical anodization method and decorated with noble metallic nanoparticles (Ag and Pt) through the photodeposition process, which forms heterogeneous structures of Ag/TiO2 nanotubes and Pt/TiO2 nanotubes. The photocatalytic performances of these samples were evaluated by the degradation rates of Methylene orange (MO) and Methylene blue (MB) under UV light. Before the investigation of their photocatalytic activity, all the samples were characterized through XRD, Raman, FE-SEM, UV-DRS, and XPS measurements. XPS indicates that the oxidation state of noble metal nanoparticles where Ag is in the metallic state Ag 0 and the presence of mixed valency states for Pt (Pt 0 and Pt II ). Pt/TiO2 nanotubes significantly enhanced photo-degradation of MO and MB resulting in 42% and 70% of its initial concentration after 3 h UV irradiation. All the samples exhibit pseudo-first-order reaction and the rate constant is found to be higher in Pt/TiO2 nanotubes for both dyes, exhibiting high photocatalytic efficiency. These can be attributed to the formation of a higher Schottky barrier that increases the trapping of electrons and results in lowering recombination rates in Pt/TiO2 nanotubes.