Microwave and Thermal Synthesis of Zinc Hydroxyl Sulfate Nanoplates

Nanomaterials present novel and environmentally friendly solutions for energy conversion, electronics, chemical sensors, and catalysts. One defining characteristic of nanomaterial synthesis is the need for precise control of size and structure (i.e., morphology). Although many zinc nanostructures have been reported the synthetic methods often sacrifice yield for quality or vice versa. Understanding the growth mechanisms of crystals will improve the design of nanomaterials. We have investigated the growth of zinc hydroxyl sulfate (ZHS) nanoplates in solution using static, continuous flow, and microwave reactions in order to understand crystal growth mechanics and its different morphologies. We hypothesize that changes in concentration, temperature, and heating rates will affect the morphology and growth of the ZHS nanpolates. We found that different morphologies can be obtained by slightly varying the concentration of the precursor solution resulting in thin plates, thick plates, double plates, and nanorods. These series of morphologies could indicate a transition from zinc oxide nanorod growth to zinc hydroxyl sulfate nanoplate growth. The resulting morphologies were analyzed using scanning electron microscopy (SEM). We have discovered that various morphologies can be obtained from the same precursor solution depending on the temperature and heating rates of the growth solution. This type of synthesis can potentially be used to grow composite morphologies in a single batch reaction. Further experiments will study the possibility of a closed system that may provide high-quality and high-yield nanostructures.