Shape-controlled synthesis of CdCO3 microcrystals and corresponding nanoporous CdO architectures

In this paper, we have demonstrated a simple ethylene glycol (EG) mediated solution method for the controlled synthesis of cadmium carbonate (CdCO3) microcrystals. The volume ratios of EG and water have a decisive impact on the morphology of CdCO3. With a decreased water volume, CdCO3 microcrystals transformed from microcubes to nanobelts. Concave microcubes, pinecone-like, and dumbbell-shaped CdCO3 microcrystals were also synthesized with moderate volume ratios of EG and water. The types of cadmium source also has great influence on the formation of CdCO3 microcrystals. Cadmium nitrate and cadmium sulfate are two effective cadmium sources for the preparation of CdCO3 microcrystals. However, pure CdCO3 microcrystals can not be obtained when using cadmium chloride as the cadmium source. The as-prepared CdCO3 microcrystals were an excellent precursor for the fabrication of nanoporous CdO micro/nanostructures via a simple thermal transformation process. This simple and controllable solution method opens an important way to fabricate nanoporous CdO micro/nanostructures.