Facile preparation of aluminium sheet-like nanostructures via one-step electrodeposition in deep eutectic solvent

Among post ionic liquid electrodeposition metal technology, choline chloride-urea (ChCl-urea) deep eutectic solvent (DES) has received much attention due to its unique physicochemical properties as well as its simple and low-cost synthesis. Herein, ChCl-urea DES is innovatively used towards one-step electrodeposition to obtain aluminium sheet-like nanostructures. The electrochemical reduction behaviour of aluminium in ChCl-urea-AlCl3 DES is investigated using cyclic voltammetry, linear scanning voltammetry, and chronoamperometry. The effect of reaction temperature on the microstructure, chemical composition, and physical phase of the products is considered. The results indicate that the reduction of Al(III) in ChCl-urea-AlCl3 DES is a diffusion-controlled one-step three-electron transfer quasi-reversible process. The increase in temperature greatly enhances the cathodic reaction kinetics and drives the reduction of Al(III) to Al. The electrodeposition of aluminium in ChCl-urea-AlCl3 DES is consistent with the instantaneous nucleation model. High purity aluminium sheet-like nanostructures with a grain size up to 100∼200 nm are obtained by the reaction for 2 h at ambient temperatures. The product aluminium phases are indexed as typical (111), (200), and (220) crystal planes. This finding provides a theoretical guide for the preparation of aluminium sheet-like nanostructures by an environmentally friendly and facile electrodeposition method in ChCl-urea-AlCl3 DES.