Role of the Deep Eutectic Solvent Reline in the Synthesis of Gold Nanoparticles.

This work presents a mechanistic understanding of the synthesis of small (<3 nm) gold nanoparticles in a nontoxic, eco-friendly, and biodegradable eutectic mixture of choline chloride and urea (reline) without the addition of external reducing or stabilization agents. Reline acts as a reducing agent by releasing ammonia ( urea hydrolysis), forming gold nanoparticles even at trace ammonia concentration levels. Reline also affects the speciation of the gold precursor forming gold chloro-complexes, stabilizing Au species, leading to an easier reduction and avoiding the otherwise fast disproportionation reaction.

Morphological Control of Nanostructured VO by Deep Eutectic Solvents.

Herein, we show a facile surfactant-free synthetic platform for the synthesis of nanostructured vanadium pentoxide (VO) using reline as a green and eco-friendly deep eutectic solvent. This new approach overcomes the dependence of the current synthetic methods on shape directing agents such as surfactants with potential detrimental effects on the final applications. Excellent morphological control is achieved by simply varying the water ratio in the reaction leading to the selective formation of VO 3D microbeads, 2D nanosheets, and 1D randomly arranged nanofleece.