Dear Nissem,

I can suggest you use silver oxalic precursors, which are easy to prepare (see paper 1 and 2), to get silver nanoparticles. These oxalates can be deposited on different substrates and also decomposed by different techniques (conventional furnace, laser etc...)(see papers 2 and 3). Slow decomposition at low temperature (about 120°C) leads to the formation of manometric particles (see paper 2). The following papers can give you an idea about the use of such metallic precursors:

1 - Kiryukhina et al. Scripta Materialia

Volume 68, Issue 8, April 2013, Pages 623-626 2 - Le Trong et al. (2017) Solid State Sciences, 69. 44-49

3- Pasquet et al. (2020) Lasers in Manufacturing and Materials Processing, 7 (4). 513-531.

Best regards.

Philippe.

Nissem Abdeljelil

It's very easy to fix a silver precursor (ammoniacal silver nitrate is often used) to a substrate and reduce in situ. Supported metal/metal alloy catalysts are a good example. Here the size and loading of the metal can be controlled relatively easily. You could also try buying in one of the silver witchcraft recipes and absorbing onto a surface but here the concentration is likely to be very low (ppm) and not controllable. Further, making your own is probably much cheaper and you'll learn more. For an overview take a look at this webinar (registration needed):

Silver colloids and invisible ink

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W150902SilverColloidInvisibleInk.html

... and the even more general:

Metal colloids - their preparation, application and characterization

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W160218MetalColloids.html

Be aware that the active bactericide is Ag+ and not Ag0. The surface of all 'silver' materials in air or water is always fully oxidized and it's the solubility of the nominal oxide that confers the properties.

In any system the Ag can be recovered by dissolution in HNO3 but AgNO3 is pretty inexpensive in relation to PGM's, for example.

Dear Nissem Abdeljelil ;

You can coat nanosilver ions from reduction method by ethanol at a temperature of 90 ̊C under atmospheric conditions in presence of linoleic acid and sodium linoleate, details in the following references;

• https://www.academia.edu/44093048/Preparation_and_Antibacterial_Activity_of_Silver_Nanoparticles
• Wang, X., Zhuang, J., Peng, Q. et al. A general strategy for nanocrystal synthesis. Nature 437, 121–124 (2005). https://doi.org/10.1038/nature03968 https://www.nature.com/articles/nature03968