Though sodium borohydride is expensive and is required in large quantities, why many researchers prefer to use it as a source of hydrogen for the reduction of nitroarenes in presence of a catalyst say nanogold?
Does it offer any special advantages over other reducing agents?
NaBH4 as LiBH4 are very strong reducers and more stable and safer than for example hyrazine.
You can try use of course hydrogen in statu nascendi, which is cheap. I used it for example to reduce graphene oxide because hydrogen in statu nascendi can be obtained from cheap substrates and is very reactive.
Dear Keya Layek
Because this compound is a cheap and potent reducing agent with near-low toxicity.
Trisodium citrate, for example, has such properties and is used abundantly as a reducing agent.
However, Sodium borohydride has some limitations too. For example, it is unable to reduce esters, amides, or carboxylic acids.
Potassium borohydride also has the same properties such as Sodium borohydride, but it is less used due to its higher price and insolubility in ethanol, ether, and THF and its severely selective performance.
Because 1. It is very effective for the reduction of aldehydes and ketons to respective alcohols.
2. It is a much milder reducing agent and comparatively safe.
Keya Layek
I discourage the use of borohyride reduction for catalyst preparation. Boron is incorporated in the matrix and metal and can act as a poison. I've preferred H2 or 5 or 10% hydrazine hydrate (products are N2 and water). Citrate reduction is often used too (Turkevitch reaction). See:
Silver colloids and invisible ink
https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W150902SilverColloidInvisibleInk.html
Some more information in:
Metal colloids - their preparation, application and characterization
https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W160218MetalColloids.html