Surfactant-free room temperature syntheses of stable colloidal silver nanoparticles in alkaline water-alcohol mixtures: pitfalls and opportunities.

Ethylene glycol in quantities as low as 5 vol% in water with only 0.5 mM NaOH rapidly leads at room temperature to silver nanoparticles. The synthesis is best initiated in the dark to lead to surfactant-free colloidal dispersions that are stable for months. The resulting nanomaterials are relevant for catalysis and beyond.