Synthesis of NaCl single crystals with defined morphologies as templates for fabricating hollow nano/micro-structures

Hollow nanostructures have a wide range of applications in nanotechnology. To accurately fabricate such nanostructures, the first and common key step is to synthesize high quality templates with controlled symmetry and geometry, ideally through a green, efficient, and economical approach. However, this has always been a challenge up to now. In the present work, we report a conceptually new simple approach, i.e., directly synthesizing templates from NaCl solutions. The properties of the templates can be tailored by selecting appropriate organic solvents and varying the crystal growth conditions. These naturally abundant NaCl single crystal templates are water-soluble, environmentally-friendly and uniform in both geometry and size, and hence are ideal for preparing high quality hollow nano/micro structures. The new approach may have the potential to replace the conventional hard or soft template approaches. Furthermore, this work has revealed the formation mechanism of nano/micron NaCl crystals with different sizes and geometries.