Site-selective deposition of binary Pt–Pb alloy nanoparticles on TiO2 nanorod for acetic acid oxidative decomposition

• Site-selective deposition for co-catalyst Pt–Pb alloy NPs was developed on TiO2.
• Photo-reduction and followed by polyol reduction lead to site-selective deposition of Pt–Pb alloy.
• Site-selectively Pt–Pb deposited TiO2 was six times higher activity than bare TiO2.
• Site-selective deposition induces efficient electron injection from TiO2 to Pt–Pb NPs, promoting oxygen reduction reaction.

Alloy nanoparticles (NPs) loaded TiO2 photocatalysts have attracted considerable attention in the recent years as a promoter of highly active photocatalysts under ultraviolet (UV) irradiation. 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 the challenging themes in TiO2 study. Herein, we present that site-selective Pt–Pb NPs deposition on rutile TiO2 nanorod by successive reduction in 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 (1 1 0) 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. 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 and 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.

Figure optionsDownload high-quality image (167 K)Download as PowerPoint slide