Dear friend Amid Laxman Sadgar

The amount of solvent used in synthesizing metal oxide nanoparticles depends on several factors, including the solubility of metal precursors, reaction conditions, and desired nanoparticle properties. In many cases, a larger volume of solvent is used than what is necessary to dissolve the metal precursors to ensure that the reaction mixture is well dispersed and homogenous, which is essential for producing uniform nanoparticles.

Additionally, a larger volume of solvent can help to prevent rapid precipitation of the metal precursors and allow for better control over the reaction kinetics.

The use of a larger volume of solvent can also affect the nanoparticle formation process. For instance, a higher volume of solvent can lead to a lower supersaturation of metal precursors and a slower nucleation rate, resulting in the formation of smaller nanoparticles. On the other hand, a lower volume of solvent can lead to a higher supersaturation and faster nucleation, resulting in the formation of larger nanoparticles. Similarly, the amount of solvent can also affect the crystal growth and Ostwald ripening processes, which can further impact the nanoparticle size and properties.

Overall, the choice of solvent volume in synthesizing metal oxide nanoparticles is a crucial factor that can affect the reaction kinetics and the final nanoparticle properties.

I generally agree with Kaushik Shandilya , with one correction: higher supersaturation and faster nucleation leads to smaller particle size, and the reverse is true for lower supersaturation. However, with high supersaturation there is more chance of forming agglomerates, which sometimes do behave like larger particles.

In addition, high supersaturation means the precipitation is very fast. This may seem useful if you're late for lunch, but otherwise it is not desirable because it tends to lead to a broad particle size distribution. When precipitation is very fast, mixing cannot compete with it; as a result different zones in the vessel "see" different degrees of supersaturation and "breed" different average particle sizes.

The mixing issue, by the way, partially explains why certain vessel sizes are more popular (beside the fact that these are the more common sizes on the shelf...).

Kaushik Shandilya and Emanuel Cooper Sir, Thank you both for your valuable comment. I certainly understand some points about it.

Hoping for more comments from other researchers so I can get conclusive.

Respected Yuri Mirgorod sir and @Alan F Rawle sir, if you could comment please.

Amid Laxman Sadgar

To obtain metal oxide nanoparticles, the sol (metal hydroxide)-gel (metal oxide) method is used. First, a sol (metal hydroxide) is obtained. It dissolves much worse than its salt predecessors. To avoid overexpenditure of the reagent and undesirable side reactions, dilute solutions are taken. Focus on the value of the solubility product of the hydroxide.