Well-aligned ZnO nanorod arrays derived from 2D photonic crystals within peacock feathers

Well-aligned ZnO nanorod arrays are successfully synthesized via a facile immersion and multi-step calcination process using the natural 2D photonic crystals found within peacock feathers as templates. The as-prepared ZnO nanorod arrays possess an array of melanin rods from the peacock feathers and exhibit tunable as well as enhanced photoluminescence in the visible range. The synthesis mechanism is investigated to reveal that the keratin component in peacock feathers can be activated by an EDTA–DMF suspension and provide more COO− groups, which could bind Zn2+ when immersed in the precursor solution. In the succeeding multi-step calcination process, keratin first breaks down at low temperature, so that melanin rods can act as the substrate template for the formation of the ZnO nanorod arrays.