Facile Fabrication of Ag−Pd Bimetallic Nanoparticles in Ultrathin TiO₂-Gel Films:  Nanoparticle Morphology and Catalytic Activity

Abstract

Ag-Pd bimetallic nanoparticles were prepared directly in ultrathin TiO(2)-gel films by a stepwise ion-exchange/reduction approach. Ion-exchange sites were created in ultrathin films using Mg(2+) ions as template. Ag(+) ion was then incorporated by ion exchange, and converted into metallic nanoparticles by low-temperature H(2) plasma, regenerating ion-exchange sites. The same procedure was then carried out for Pd(2+) ion, producing Pd-on-Ag bimetallic nanoparticles, as TEM observation and plasmon resonance absorption indicate. By contrast, reversed metal incorporation procedure appeared to give a mixture of individual Ag and Pd nanoparticles, as confirmed by TEM, absorption spectroscopy and X-ray photoelectron spectroscopy. For hydrogenation of methyl acrylate, the catalytic activity of the Pd-on-Ag nanoparticle is 367 times as large as that of commercial Pd black and 1.6 times as large as that of Pd monometallic nanoparticle. The outstanding catalytic activity was explicable by the large fraction of the surface-exposed Pd atoms. The formation process of the bimetallic nanoparticle and their general morphological feature are discussed.

Regulations of silver halide nanostructure and composites on photocatalysis

“…Moreover, in plasmonics, metal or even noble metal are the noumenon particles (such as Cu, Au, and Ag), which promises their resistance to decomposition. Based on these two advantages, plasmonic nanoparticles (NPs) are considered as favorable photosensitive materials for enhancing the light absorption coefficient of large bandgap semiconductors and could also maintain their stabilities [87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102]. Great quantities of works on constituting plasmonic NPs and largebandgap semiconductors have already achieved.…”

Synthesis and functionalities of noble metal nanoparticles formed through simple all-inorganic photochemical procedures

“…Compared to the spectrum of a bare film (Figure 10(a)), spectra of Figure 10(b) and (c) depict a large band centred at around 515 nm and extending over a wide spectral range. Location and shape of this band closely corresponds to the plasmon band of metal silver nanoparticles dispersed at a solid surface [55,[63][64][65][66][67]. Figure 10(b) and (c) also shows that, for the same immersion durations, the plasmon band intensity increases when increasing the SN concentration in solution.…”

Bimetallic Au/Ag Metal Superstructures From Macromolecular Metal Complexes in Solid-State

“…For the other pyrolytic product similar SEM/EDS images were observed. The nature of the Au/Ag bimetallic materials become clear by observing the quantitative ESD analysis where an approximate content Au/ Ag of 2:1 characteristic of core/shell 38,39 was observed see Figure 5. A possible representation of these are given in Figure 6.…”