Electrochemical deposition of hierarchical micro/nanostructures of copper hydroxysulfates on polypyrrole-polystyrene sulfonate films

Copper-based hierarchical micro/nanostructures were prepared using a novel electrochemical route on polypyrrole-polystyrene sulfonate (PPy-PSS) thin films. The resulting structures are composed of copper hydroxysulfates, as confirmed by the electrochemical, spectroscopic, and X-ray diffraction characterization. The electrochemistry of the film is a key factor in the overall deposition of the micro/nanostructures. The PPy-PSS films capture cations from the copper sulfate electrolyte solution and facilitate the reduction of dissolved oxygen to hydroxide ions. The system then acts like a nanoreactor as the Cu²⁺ and OH^- ions are concentrated on the polymer surface, which in the presence of the SO₄^2- ions from the electrolyte solution results in the electrocrystallization of the copper hydroxysulfates hierarchical structures.