Sn‐Based Alloys Synthesized in an Ionic Liquid at Room Temperature: Cu₆Sn₅ as a Case Study

Abstract

Sn‐based alloys are increasingly investigated owing to possible electronic/structural modulations of interest for electrocatalysis and energy storage applications. Here, we report on the use of a chemical system consisting of an ionic liquid (1‐ethyl‐3‐ methylimidazolium bis(trifluoromethanesulfonyl)imide: [EMIm+][TFSI−]) and Sn‐based precursor Sn(TFSI)2 both featuring similar anionic groups. This strategy increases the solubility of the cationic precursor in the IL and avoids the formation of side‐products during the precipitation of Sn‐nanoparticles formed upon reaction with a reducing agent (NaBH4). Using NMR relaxometry, we further established that these nanoparticles are stabilized by specific interactions with the cationic group of the IL. Targeting the composition Cu6Sn5, we further demonstrated that this approach can be used to prepare Sn‐based alloys which could not be prepared using conventional chloride‐based precursors.