Fabricating Well-Dispersed Nanosized Gold Catalyst on Titanate Nanowires Surface for 4-Nitrophenol Reduction

Abstract

In this paper, homogenous gold nanoparticles (AuNPs) with a high density and a narrow size distribution were successfully fabricated on titanate nanowires (TNWs) sca®olds in the absence of organic capping agents. An ameliorated low-temperature hydrothermal method was used to prepare the TNWs sca®olds like bird's nest on the Ti substrate, and the nanowires diameter was about 30-80nm. Then, AuNPs were synthesized on the TNWs sca®olds with a depositionprecipitation urea (DPU) method. The TEM and XRD measurements indicated that well-crystallized face-centered cubic (fcc) AuNPs were homogeneously dispersed on TNWs, and AuNPs with average sizes of 2.7 nm and 4 nm were obtained, respectively for the theoretical gold loading 5 wt.% and 8 wt.%. Inspiringly, the 8%-AuNPs/TNWs catalyst could reduce 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) within 210 s, and exhibited better catalytic reduction performance than that of 5%-AuNPs/TNWs.

Atomic scale characterization and surface chemistry of metal modified titanate nanotubes and nanowires

“…A simple two-step procedure was developed for preparing highly efficient AuNPs/TNWs composite catalyst for 4-nitrophenol reduction [401]. The results showed that AuNP were crystalline with active planes such as (111), (200), (220), (311) and (222).…”

Influence of gold additives on the stability and phase transformation of titanate nanostructures

“…Atomically dispersed gold can be produced on porous TiO 2 and titania nanostructures (nanotubes, nanowires) by coprecipitation or deposition-precipitation methods. 29,[23][24][25]30 Although it is virtually impossible to prepare a truly monodisperse collection of metallic particles (i.e. particles of exactly the same diameter), in the past years significant progress was made in the preparation of gold particles with a narrow diameter distribution between ~2-10 nm.…”

“…11,[19][20][21] Recently it was found that titanate nanostructures (nanowires and nanotubes) can stabilize gold in a very dispersed form. 21,[23][24][25][26][27][28][29][30] Up to now some important titanate supported gold catalytic reactions were discovered. Gold-containing titania nanotubes were found to display higher activity than the Degussa P-25 catalyst in the photo-oxidation of acetaldehyde, 25 in the photocatalytic degradation of formic acid, 12 in the water-gas shift reaction 23 and in CO oxidation 23,[27][28][29] .…”

“…Nanosized gold catalyst on titanate nanowires exhibited excellent efficiency in 4-nitrophenol reduction. 30 There are some examples that other noble metals supported on titanate nanostructures also perform remarkably in catalytic processes. TiO 2 nanofibers decorated either with Pt or Pd nanoparticles show significant photocatalytic behavior as demonstrated by the decomposition of organic dyes in water, the degradation of organic stains on the surface of flexible freestanding cellulose/catalyst composite film and the generation of hydrogen from ethanol using both suspended and immobilized catalysts.…”

Titanát nanoszerkezetek és fémek felületi kölcsönhatásai: ioncsere vagy klaszterképződés?

“…Bár szigorúan véve teljesen monodiszperz részecskéket nem lehet elõállítani, az utóbbi évek erõfeszítései nyomán 2-10 nm közötti átlagos átmérõvel már sikerült kontrollált rendszereket létrehozni [21][22][23][24][25][26][27] . A 4. ábrán két különbözõ módon titanát nanoszálra felvitt aranyrészecskék TEM képei láthatók.…”