Electrically driven cation exchange for in situ fabrication of individual nanostructures

Abstract

Cation exchange (CE) has been recognized as a particularly powerful tool for the synthesis of heterogeneous nanocrystals. At present, CE can be divided into two categories, namely ion solvation-driven CE reaction and thermally activated CE reaction. Here we report an electrically driven CE reaction to prepare individual nanostructures inside a transmission electron microscope. During the process, Cd is eliminated due to Ohmic heating, whereas Cu+ migrates into the crystal driven by the electrical field force. Contrast experiments reveal that the feasibility of electrically driven CE is determined by the structural similarity of the sulfur sublattices between the initial and final phases, and the standard electrode potentials of the active electrodes. Our experimental results demonstrate a strategy for the selective growth of individual nanocrystals and provide crucial insights into understanding of the microscopic pathways leading to the formation of heterogeneous structures.

Developments of cation-exchange by in situ electron microscopy

“…just in a region of the already intercalated nanoplatelets. Finally, it is noteworthy mentioning the work of Zhang et al [37], dealing with an electrically driven in situ CE reaction. Here, a single CdS nanowire was put between two electrodes, one of which was constituted by copper and acting as a cations source.…”

“…The previous chapters aimed at providing with a general review of the results obtained in performing CE reactions at the solid state by an in situ heating (S) TEM approach. To the best of our knowledge, the above-reported works, together with few further interesting and recent ones [35][36][37], constitute the whole literature currently available on such a kind of investigations performed by in situ (S)TEM methods. In particular, the paper of Yalcin et al [35] reports that in nanodumbell-shaped heterostructures constituted by CdSe and PbSe undergoing in situ heating between 160°C and 200°C, CE occurred at the interface between the two semiconducting single crystal domains.…”

Surfactant-Assisted Cooperative Self-Assembly of Nanoparticles into Active Nanostructures

“…It also requires ordered NP assemblies as the starting materials to accomplish the stress-induced tuning of phase transition and interparticle separation. Another interesting direction in the NP community is the synthesis of hybrid nanocrystals through nanocrystal or ion diffusion in solutions to control nano-heterogeneous structures (Cozzoli et al., 2006, Ghosh and Manna, 2018, Zhang et al., 2017a, Pang et al., 2013, Pang et al., 2016, Erwin et al., 2005). Finally, increasing structural complexity by combining with other top-down and bottom-up methods is one of the natural directions for nanoscience.…”

Electrochemically Driven Cation Exchange Enables the Rational Design of Active CO2Reduction Electrocatalysts

“…In turn, these reactions could enable the synthesis of advanced CO 2 RR catalysts that are otherwise inaccessible by previously reported de novo synthetic techniques . However, owing to the nature of the driving forces governing CE, traditional CE methods exhibit some intrinsic limitations for the direct preparation of high‐performance CO 2 RR catalysts on electrode surfaces. For example, the extensively explored solution‐based CE is typically restricted to colloidal NCs, and mainly driven by adjusting solution‐added ligand environments .…”