A little remained of the experiments conducted previously.
Colourless NaBr(aq) / NaCl(aq) solution was placed into a clean, dry beaker. This was followed by the addition of colourless silver nitrate solution, which produced a pale yellow precipitate forming silver bromide. We were able to collect precipitate on the solution.
During this week, we did the following:
Sonication* of silver bromide crystals before irradiation with photons increases the amount of silver reduced.
This solution was irradiated with UV light, during which photons of light initiate redox processes of silver bromide to form silver nanoparticles and bromide ion. We irradiated and sonicated (irradiation – sonication – irradiation sonication) for different time intervals for three times.
After irradiation with 285, 300, and 365 nm UV light lamp, the silver bromide crystals were then washed with ultra-pure water and vacuumed out of the solution.
A change in color was seen, which is a great accomplishment. We have silver nanoparticles.
This silver nanoparticles were washed and vacuumed out of the solution. The resultant bromide ion was wasted. The silver nanoparticles have been recycled at this point. Placing silver nanoparticles into water containing bromide ion produces silver bromide again.
*Sonication is the act of applying sound energy to agitate particles in a sample.