I'm doing gold reduction by using sodium borohydrate as the reducing agent.
Under room temperature, the 20ml 1.0mM HAuCl4 is placed on the stir plate, 0.5ml of 1% NaBH4 is added into it.
It showed a little dark violet for 1 second, then the solution turns into clear light yellow color in the end.
Is this correct, or it should be like the citrate reduction, in dark ruby red color?
Please help.