ZIF-8 self-etching method for Au/Polydopamine hybrid cubic microcapsules with modulating nanostructures
Metal-organic framework (MOF) derived nanostructures exhibit wonderful characteristics and possess broad application by modulating the complex composition and inner nanostructure. Although various MOF based nanocomposites have been successfully developed, a facile method that can easily turn the structure dependent chemical component of the MOF derived hybrids remains a challenge. By coating the zeolitic imidazolate framework-8 (ZIF-8) with Au/Polydopamine (Au/PDA) via a in situ redox-oxidize polymerization of HAuCl4 and dopamine, this work found the ZIF-8 templates were simultaneously etched off to give Au/PDA hybrid microcapsules with a cubic shape. This one-step sacrifice templating process followed a competing chelating between gold ions and Zn2+ cations to 2-methylimidazole and PDA, thus both the hollow and yolk-like hybrid cubic microcapsules were controllably obtained by varying the synthetic dynamics. Owing to the hollow nature, penetrated PDA shell, well-distribute Au nanocrystals, and unique stable nanostructure, the non-spherical Au/PDA hybrid cubic microcapsules showed high performance in catalyzing the reduction of 4-nitrophenol as well as adsorption/releasing of ibuprofen as a model drug. Moreover, this simple strategy offers a controllable design in developing multifunctional nanocomposites with definite inner nanostructure and activities for nanocatalysis, drug delivery, and energy storage etc.