Site-Selective Binary Alloy Nanoparticles Deposition on TiO2 Nanorod for Acetic Acid Oxidative Decomposition Under UV-Vis Irradiation

Abstract

Alloy nanoparticles (NPs) loaded TiO2 photocatalysts have attracted considerable attention in recent years as a promoter of highly active photocatalysts under ultraviolet (UV) irradiation [1]. Many synthetic techniques have been utilized in preparation of binary alloy NPs loaded TiO2. However, control of deposition site for alloy NPs on TiO2 is one of a challenging theme in TiO2 study. Herein, we present that site-selective Pt-Pb NPs deposition on rutile TiO2 nanorod by successive reduction of metal ions, photo-reduction of Pt4+ and followed by microwave assisted polyol reduction of Pb2+ (2-step method). The Pt-Pb NPs were site-selectively deposited on the reduction site on (110) surface of the rutile TiO2 nanorod. The photocatalytic activity of rutile TiO2 was significantly enhanced after Pt-Pb NPs loading for oxidative decomposition of AcOH in aqueous phase as shown in following figure. The AcOH was completely oxide to CO2 and the CO2 evolution of the site-selectively Pt-Pb NPs deposited TiO2 was nearly six times higher than that of a bare rutile TiO2 and three times higher than randomly Pt-Pb NPs deposited TiO2. The well mating of the reduction reaction site on photocatalyst, TiO2, and deposition site for co-catalyst, Pt-Pb NPs, induces efficient electron injection from photocatalyst TiO2 to co-catalyst Pt-Pb NPs, promoting oxygen reduction reaction, reduction process of AcOH oxidative decomposition. The accelerated electron consumption in reduction process leads to smooth oxidative decomposition of AcOH at oxidation site. These findings suggest that the site-selective deposition of alloy NPs is a predominant way to bring out catalytic performance of co-catalyst alloy NPs on TiO2. [1] T. Gunji, A. J. Jeevagan, M. Hashimoto, T. Nozawa, T. Tanabe, S. Kaneko, M. Miyauchi, F. Matsumoto, Appl. Catal B 181 (2016) 475-480. Figure 1