Influences of Silver and Halide Ions

Another mechanism has also been proposed where silver halide is grown epitaxially, as a precipitation, on the growing gold surface [38]. Nonetheless, since other polymers such as PEI or poly (acrylic acid) failed to produce the expected nanorod, it seems certain that CTAB plays a further important role in seed-mediated crystal growth (see Section 7.5.2.6). 

For the electrochemical synthesis of gold nanocrystals, bulk gold and platinum electrodes are used as the anode and counter-cathode, respectively, in the simple two-electrode system [23, 26,110]. It is postulated that oxidized gold ions from the anode are recrystallized at the cathode under the influence of a surfactant such as CTAB. The major product was nanorods of single crystalHne lattice with a dimension of-lOOnm, that differed from the penta-twirmed nanorods formed in seed-mediated growth [76]. The morphology may be further tuned to nanocubes by the systematic addition of acetone and the concomitant appHcation of ultrasound. The cubes were mostly bounded with 100 planes, as observed in the polyol synthesis [26]. 

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