In situ AFM observation of the electrochemical reduction of a single silver sulphide crystal and the recrystallization of the resulting silver crystal

Single silver sulphide (Ag2S) crystals immobilized on gold electrodes and possessing edge lengths of about 400 nm, were electrochemically reduced to silver. In situ recorded AFM images clearly show how the reaction starts at the three-phase junction gold-Ag2S-solution. The initial reduction product is a hump of silver atoms that is rather soft and that is clearly affected by the tip motion. Within minutes, this amorphous hump of silver atoms recrystallizes and attains the well-developed shape of a silver single crystal.