2018 Volume 81 Issue 1 Pages 41-47
Effects of silver-halide base to the preparation of gold nanoparticles by gold-deposition development were analyzed by postfixation development on lonely latent image specks after the removal of silver halide or carbon-replica observation of silver-halide grains with depositing gold particles. Results of the postfixation development suggested that the acceleration of development rate by addition of ascorbic acid (AA) in the developer was due to the direct reduction of Au (I) ions by AA. Gold particles formed on silver halide surface at high concentration of AA had many fine protrusions, and participation of silver filaments formed by reduction of silver halide with AA was suggested. This acceleration by AA was more remarkable on octahedral grains than on cubic grains, and was due to the difference of latent image formation process. Effects of the crystal faces on silver-halide grain to the gold-deposition development process itself were not so significant.
