However, the strategies explored in previous reports did not offer a suitable size control to perform sizeeffects studies. Such size effects studies are primordial in nanoscience. To date, to achieve size control by a RT SF approach in alkaline mixtures of water and mono-alcohols, the options are (i) to mix ethanol and methanol while keeping the alcohol content around 30 v.% (higher methanol contents lead to larger NPs) , or (ii) use different amount of base, with a relatively strong influence of small changes in the base concentration on the NP size , or (iii) use different lights environments . None of these strategies (i-ii) is optimal to achieve a fine size control relevant for size effects studies, or are relatively complex strategies requiring specific equipment (iii). Here, we report a simple(r) fourth (iv) strategy to achieve size control by this synthetic approach and show the benefits to perform size effects studies with the example of SF Au NPs for alcohol-electro-oxidation reactions.