Reducing agents and processes

In some cases the particle morphology can be varied by the selection of the reducing agents. The silver nanorods can be obtained by the variation of reducing agent efficiency and the seed-mediated growth method, the latter involves at least two steps [299, 300]  

1) the preparation of small size spherical silver nanoparticles, and 

2) growdh of the prepared spherical particle in surfactant (CTAB) media. 

In the first step, silver nanoparticles with diameters ca. 6 nm were formed by chemical reduction of AgNOs with a strong reducing agent such as NaBH4 in the presence of sodium citrate dihydrate to stabilize the nanoparticles  

Prepared spherical silver nanoparticles are then added to a solution containing more silver salt, a weak reducing agent (ascorbic acid) and a surfactant (CTAB). Ascorbic acid is a weak reducing agent and cannot reduce the silver salt in the present of the micelle without the presence of seeds [301]  

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