Growth of different morphologies of silver submicrostructures: the effect of concentrations and pH

In this letter, we demonstrated the growth of different morphologies of silver submicrostructures influenced by ortho-phenylenediamine (oPD) concentrations and pH values. The results indicated that concentration ratios of the oPD to Ag+ colloids in the solution determine the final morphology of the products. oPD is found to act as a stabilizer as well as reduction agent. Particle shape ranges from sheets to spheres, increasing with molar ratio. Meanwhile, morphologies of structures and the time consumption to form particles both depend on pH values. We could obtain plates, polyhedrons, spheres, and dendrites through adjusting pH from 1.3 to 12.3. A mechanism is proposed to interpret the controlled synthesis of silver submicrostructures.