Preparation of Monodisperse Au/TiO₂ Nanocatalysts via Self-Assembly

Abstract

In this work, we report that presynthesized metallic nanoparticles (such as gold nanoparticles), rather than on-site growing ones that are prepared under thermally or photochemically activated conditions, can be “impregnated” uniformly onto premade oxide supports with organic interconnects which have bifunctional groups. Methodic features of this general technique have been demonstrated using a model metal−oxide system, Au/TiO2 (TiO2 in anatase phase) catalyst, in the photodegradation of organic compounds (e.g., methyl orange). On the basis of our investigations with a range of analytical techniques, it has been further found that, if desired, permanent engagement and direct contact between the supported metals and oxide carriers can also be achieved with additional heat treatments. In principle, other oxide-supported metal catalysts can also be fabricated at low temperatures through these types of self-assembling routes.

Effect of Au nano-particles on TiO2 nanorod electrode in dye-sensitized solar cells

“…Initial demonstrations of DSSCs were based on dye sensitization of porous nano crystalline semiconductors like TiO 2 . There are numerous studies on the potentials of improving the efficiency of DSSCs by using other semiconducting metal oxides, such as Nb 2 O 5 [3], CeO 2 [4], ZnO [5,6], and SnO 2 [7] and composite oxide materials [8,9].…”

Toward compositional design of reticular type porous films by mixing and coating titania-based frameworks with silica

“…19 The XPS spectra of the (pure) titania film showed the presence of Ti 4+ species (e.g., TiO 2 ) because symmetric Ti 2p3/2 and Ti 2p1/2 peaks were observed at around 456 eV and 464 eV, respectively. 24,25 The O 1s peaks were respectively observed at around 530 eV and 532 eV by the presence of oxygen in bulk TiO 2 and adsorbed H 2 O. 25 A similar profile was recorded in the Ti 2p XPS spectrum of the titania-silica film (at around 459 eV and 465 eV), revealing the presence of similar titania frameworks.…”

“…24,25 The O 1s peaks were respectively observed at around 530 eV and 532 eV by the presence of oxygen in bulk TiO 2 and adsorbed H 2 O. 25 A similar profile was recorded in the Ti 2p XPS spectrum of the titania-silica film (at around 459 eV and 465 eV), revealing the presence of similar titania frameworks. An enhanced O 1s peak was observed at 532.4 eV after mixing silica and ascribed to the oxygen in silica frameworks.…”

“…Symmetric Ti 2p3/2 and Ti 2p1/2 peaks were observed at around 465.5 eV and 467 eV after silica coating and subsequent calcination, indicating that main frameworks of the reticular type structures are actually constructed by titania. 24,25 A very strong O 1s peak was observed at around 534 eV because of the enough silica coating, while a small peak was observed at around 531 eV. In this case, the peaks are ascribed to three components such as oxygen atoms in titania cores (TiO 2 ), coated silica domains (SiO 2 ), and the interfaces (Si-O-Ti bonds).…”

Preparation of Pt catalysts decorated TiO2 nanotube arrays by redox replacement of Ni precursors for proton exchange membrane fuel cells

“…Since the development of high aspect ratio self-organized TiO 2 nanotubes (TNTs) array, the use of TiO 2 as an efficient catalyst support that provides a highly 3D-nanoarchitecture has even further widened. Recently, some works have been conducted to study the growth of Pt-modified TNTs, among which Pt was deposited via various processes, including photochemical deposition, conventional impregnation techniques, and colloid methods [8][9][10][11][12]. However, these methods cannot be used to deposit metal particles inside high aspect ratio porous materials and the advantage of TNTs in high specific surface area is limited.…”