Nanomaterials and nanoparticles (NPs), e.g. gold nanoparticles (Au NPs), express unique properties that are relevant for applications in multiple areas of research and development, e.g. in catalysis, sensing, optics, electronics or medicine. Regardless of the application considered, the full exploitation of NP properties require their controlled syntheses. Various recipes have been reported for the preparation of Au NPs and there is an increasing awareness and need for the NPs to be produced by green and sustainable methods. We recently reported a very simple synthesis of gold (Au) NPs combining a range of desirable features. The synthesis is simply achieved by adding HAuCl4 to alkaline water and mono-alcohol mixtures, and builds up on previous work using preferentially polyols such as glycerol. The method does not require the typical additives / stabilizers and/or high viscosity chemicals commonly used. Since no additives with a molar mass higher than 100 g mol -1 apart from the metal precursor is required, this approach qualifies as surfactant-free, as per a definition proposed and detailed elsewhere. This room temperature surfactant-free synthesis is surprisingly simple, can be performed using ca. 20 v.% ethanol as the source of reducing agents, i.e. a cheap, relatively low toxicity and low viscosity chemical. The method is largely detailed elsewhere and leads to size controlled NPs in the range 5-30 nm. Despite the absence of common additives, the method leads to colloidal dispersions of NPs stable for months and even years. The use of different alcohols leads to relative pros and cons summarized in Table . Our recent investigation of the effect(s) of using different alcohols for the room temperature synthesis of the surfactant-free Au NPs showed that different formation pathways are followed for different alcohols used, namely: methanol, ethanol, ethylene glycol, glycerol. The synthesis is faster in glycerol and lead to relatively small size NPs in the range 5-10 nm over a wide range of conditions (e.g. different concentrations of base and/or alcohol contents). The synthesis using glycerol is also less sensitive to the light environment. The glycerol-mediated synthesis is therefore overall more robust. However, a major drawback of the glycerol-mediated synthesis is the use of a relatively viscous solvent. The high viscosity of polyols prevent a simple and direct use of the Au NPs. Ethylene glycol is a suitable alternative to glycerol, 32 but is still a viscous solvent. Ethanol presents the main benefit to have a very low viscosity: A desirable feature to more easily process the NPs, e.g. to deposit the NPs on various surfaces to develop heterogeneous catalysts without the need for intensive and wastegenerating steps typically requiring strong acids when polyols are used. Ethanolmediated syntheses still lead to rather small ca. 10 nm Au NPs stable for years. Nevertheless, the overall kinetics of NP formation are slower and the experimental window where the synthesis can be considered successful is narrower than in the case of polyols-mediated syntheses. It is here considered that desirable features for a synthesis are to lead to small size NPs, in a relatively timely approach, through a robust process and ideally in low viscosity solvents to facilitate the use and processing of the Au NPs. As presented in Table , the use of polyols does not fulfil the requirement of low viscosity but the use of the low viscosity ethanol is more sensitive to the variations of various parameters. Note that the use of methanol is here excluded due to the high toxicity of methanol and the fact that methanol-mediated syntheses lead to larger ca. 10-30 nm NPs, whether methanol is used as sole source of reducing agent or mixed with ethanol. Here, the increased understanding of the similitudes and differences between the use of glycerol and ethanol established in our previous work leads us to investigate and develop new synthetic approaches and explore the possible benefits of using [monoalcohol + polyols] mixtures as the source of reducing agents, with a focus on high mono-alcohols content. To the best of our knowledge, the strategy to use [ethanol+glycerol] mixtures to optimize surfactant-free syntheses of Au NPs has not been reported yet. It is established that small amount of glycerol around 1-2 v.% are beneficial to achieved size control in syntheses performed with a total amount of alcohol around 20 v.%. The results pave the way to greener syntheses of Au NPs and more sustainable nanotechnologies.