Formation of Au nanoparticle-doped PVK microcapsules and foam-like structures at the liquid/liquid interface

Highlights: ► Au nanoparticle-doped microcapsule and foamlike film of PVK formed at the liquid/liquid interface. ► These composites formed due to self-assembly of polymer molecules at the interface. ► Au nanoparticles were produced simultaneously and doped in the films. ► The composite films exhibited effective catalytic properties. ► Durable catalytic activity was achieved after the second cycle. - Abstract: Gold nanoparticle-doped microcapsules and foamlike films of poly(N-vinylcarbazole) (PVK) were prepared through a self-assembly process at a liquid/liquid interface. The liquid/liquid interface was formed by an aqueous solution of HAuCl4 and a chloroform solution of PVK. The composite structures were characterized using transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and UV-vis spectroscopy. The results revealed that microcapsules with the size of several hundreds of nanometers and foamlike thin films were formed, and small gold nanoclusters and nanoparticles embedded in the walls. The formation of these composite nanostructures was the result of the adsorption and combination of PVK molecules with AuCl4− ions, self-assembly of the composite molecules, and reduction of the complex ions at the liquid/liquid interface. The composite structures exhibited effective catalytic activity for the reduction of 4-nitrophenol (4-NP) by KBH4 in aqueous solutions.