Self-catalytic growth of one-dimensional materials within dislocations in gold

Abstract

Dislocations in metals affect their properties on the macro- and the microscales. For example, they increase a metal’s hardness and strength. Dislocation outcrops exist on the surfaces of such metals, and atoms in the proximity of these outcrops are more loosely bonded, facilitating local chemical corrosion and reactivity. In this study, we present a unique autocatalytic mechanism by which a system of inorganic semiconducting gold(I) cyanide nanowires forms within preexisting dislocation lines in a plastically deformed Au-Ag alloy. The formation occurs during the classical selective dealloying process that forms nanoporous Au. Nucleation of the nanowire originates at the surfaces of the catalytic dislocation outcrops. The nanowires are single crystals that spontaneously undergo layer-by-layer one-dimensional growth. The continuous growth of nanowires is achieved when the dislocation density exceeds a critical value evaluated on the basis of a kinetic model that we developed.

Deformation twin traces on gold surfaces: A pathway to tailored epitaxial growth of 1D semiconductors

“…S8 ). Regrettably, AuCN crystals in the lamellae could not be detected by HRTEM, since AuCN decomposes rapidly upon exposure to high-energy electron beams ( 40 , 52 , 67 , 68 ). Since the cross-section lamellae were produced via PFIB, the sample preparation process is likely to have already caused the decomposition of AuCN crystals prior to their exposure to the HRTEM electron beam.…”

“…In our previous work ( 40 ), we introduced a method of synthesizing gold(I)-cyanide (AuCN) single crystal nanowires through an autocatalytic reaction, initiated at dislocation outcrops on the surface of highly deformed bulk samples of Au-Ag alloy during selective dealloying. In that study, we demonstrated that the presence of a high density of dislocations facilitated the propagation of autocatalytic reaction, leading to the subsequent growth of semiconductor nanowires made of AuCN.…”

Laser-Induced Activation of N2 and Catalyst-Free Synthesis of HCN

“…Accordingly, the use of N 2 and CH 3 OH to synthesize HCN would be extremely intriguing both scientifically and industrially. It is worth noting that the direct utilization value of HCN would increase by safely converting it into inorganic cyanides with lower toxicity during the conversion of N 2 to HCN. , Previously, graphene was used to catalyze the synthesis of silver cyanide particles from silver nitrate and ethanol, and the use of two-dimensional materials as substrates for the synthesis of one-dimensional cyanide chains was also reported. − Therefore, direct synthesis of HCN from N 2 followed by in situ fixation into inorganic cyanides requires the purification and separation of HCN, which can greatly diminish the hazards of HCN.…”