Large-scale metal oxide nanostructures on template-patterned microbowls: A simple method for growth of hierarchical structures

Hierarchical structures–metal oxide nanostructures on desired patterns of metal oxide microbowls have been successfully fabricated by combining the unique advantages of two simple techniques: template assisted self-assembly technique by which polystyrene micro/nanospheres could be readily patterned and positioned on a large scale and hot-plate technique by which metal oxide nanostructures could be easily formed. Instead of using microspheres as mask to locate the catalyst for subsequent nanostructure growth, in this work we directly employed the patterned polystyrene microspheres as a template where the metal films (Fe, Cu, Zn and Co) were deposited and the hierarchical structures were formed subsequently by a one-step low temperature (250 °C–400 °C) heating process in atmosphere. With the feasibilities like patterning, positioning and fabricating the hierarchical structures with large surface area, this simple and practical method exhibits potentials for the synthesis of a unique building block: nanostructures on the desired patterns of micro/nanobowls, for future nanoscience and nanotechnology.