Chemical- or Radiation-Assisted Selective Dealloying in Bimetallic Nanoclusters

Abstract

A selective dealloying in bimetallic nanoclusters prepared by ion implantation has been found upon thermal annealing in oxidizing atmosphere or irradiation with light ions. In the first process, the incoming oxygen interacts preferentially with copper promoting Cu2O formation, therefore extracting copper from the alloy. In the second process the irradiation with Ne ions promotes a preferential extraction of Au from the alloy, resulting in the formation of Au-enriched "satellite" nanoparticles around the original AuxCu1-x cluster.

Cookie‐like Au/NiO Nanoparticles with Optical Gas‐Sensing Properties

“…Moreover, the same strategy has successfully been applied in defining the optical absorption of similar partial core/shell Au-Cu 2 O nanoclusters. [14,15] Comparable simulations made by assuming ellipsoidal cluster shapes did not give the same level of agreement. Hence, the principal result of the optical simulation is that the most intense absorption band is controlled by dielectric coupling at the Au/NiO interface, which red-shifts the position of the Au SPR band.…”

“…This result suggests a possible islandlike growth of the oxide, directed by the underlying Au template. It is interesting to highlight that we obtained a similar twofold coherent topology in studying the dealloying processes under thermal annealing for bimetallic Au-Cu nanoclusters in silica obtained by ion implantation, [14] where upon short annealing in an oxidizing atmosphere Au-Cu alloy nanoclusters were converted to an fcc Au-rich phase partially surrounded by a coherent fcc Cu 2 O shell.…”

Dependence of the irradiation-induced growth kinetics of satellites on the nanoclusters dimension

“…Experimentally, it has been shown that the irradiation favors the satellites formation around the original NC [5][6][7][8][9]. In particular, ion irradiation can be used to induce the selective precipitation of one element in bimetallic alloys [6].…”

Ageing of mass-selected Cu/Au and Au/Cu core/shell clusters probed with atomic resolution

“…in electronics, biodiagnostics and catalysis [1][2][3][4][5][6][7][8][9]. The gold (Au)-copper (Cu) system is of particular interest [2,[10][11][12][13][14][15][16][17][18][19][20][21][22]. Recent studies have shown that Au-Cu bimetallic clusters are promising novel catalysts for CO oxidation, propene epoxidation and benzyl alcohol oxidation [12][13][14].…”