Accelerated growth from amorphous clusters to metallic nanoparticles observed in electrochemical deposition of platinum within nanopores of porous silicon

Abstract

This study examined the formation of amorphous platinum (Pt) clusters in nanopores of porous silicon at an initial stage of pore filling. The time dependency of the chemical state and local structure of Pt in the nanoporous silicon were characterized by X-ray absorption fine structure spectroscopy (XAFS). Initially, the Pt deposits showed non-negligible amounts of PtO 2 , formed by surface oxidation from the atmosphere, suggesting that the particle size was quite small. Deep analysis of extended XAFS (EXAFS) strongly suggested that Pt at the early stage of deposition was amorphous. The mechanism of amorphous Pt formation is discussed based on the confinement effect for Pt complex anions in nanopores.

Optimisation of the electrochemical performance of (Nd,Gd)1/3Sr2/3CoO3−δ cathode for solid oxide fuel cells via spray-pyrolysis deposition and decoration with Ag nanoparticles

“…The thin Ag 2 O layer likely rationalises the absence of significant observed effects in the local structure of the nanometric particles, such as lattice collapse or amorphisation. 34,35 Nevertheless, the decrease in intensity of the Ag white-line of the XANES data in the composite in comparison to that of the bulk metallic standard provides evidence of the small particle size, since small metal particles present a distorted electronic structure with incomplete d orbitals with respect to the bulk state, diminishing the white-line intensity.…”

Low-Temperature Ammonia Oxidation in a Microchannel Reactor with Wall-Loaded X(X = Pt, Pd, Rh, PtPdRh)/TiO2 Nanotube Catalysts

“…Platinum was loaded on the as-prepared supports via facile photocatalytic reduction deposition. ,, Potassium chloroplatinate, the precursor, was dissolved in 10 mL of deionized water, with 0.2 mL of formic acid serving as a scavenger. Then, the plate support was immersed in solution and irradiated for 2 h with a 500 W ultraviolet lamp.…”

The effect of rare earth element cerium on electrocrystallization and microstructure of nickel deposits

“…The addition of CeCl 3 increases the concentration of rare earth ions, enhances the electrolyte migration rate, reduces the thickness of the diffusion layer, decreases the diffusion resistance of discharge ions to the cathode surface, accelerates the diffusion rate of discharge ions to the cathode surface, and speeds up the nucleation process. The optimal addition concentration of CeCl 3 is 0.8 g•L -1 because it shortens the nucleation relaxation time, thereby accelerating the electrodeposition rate of nickel ions on the cathode [12].…”