Facile Synthesis and Fine Morphological Tuning of Ag2O

The morphological evolution of the Ag2O cubic crystal system was examined with the goal of controlling and fine-tuning the morphologies of the microcrystalline products. A variety of Ag2O microcrystalline shapes could be prepared through the reduction of a silver-pyridine complex in solution at room temperature. The concentrations NaOH and AgNO3 significantly affected the morphology of the Ag2O final product. The Ag2O morphology evolved from a simple truncated cube to an 8-pod with three arms along the ⟨111⟩ directions as the concentration of NaOH increased. The Ag2O morphology evolved from an edge-truncated cube to a rhombic dodecahedron as the total reactant concentrations increased, holding the AgNO3/pyridine/NaOH molar ratio constant. The morphological evolution from an 8-pod to a rhombic dodecahedron via an 8 × 3-pod, a 6 × 4-pod, a smoothed squared 6-pod, a concave rhombic dodecahedron, and a truncated rhombic dodecahedron was also observed. The crystal growth mechanism underlying the morphological evolution of Ag2O microcrystals is discussed.