Carbon nanotube thin films modified with a mixture of Prussian blue and ruthenium purple: combining materials and properties

Thin films of iron-filled carbon nanotubes prepared through the liquid/liquid interfacial method were modified with a mixture of hexacyanometallates (HCMs) Prussian blue and ruthenium purple. Two different approaches were used in order to obtain both materials in the composites, based on a direct reaction starting from a mixture of both precursors or a step-by-step deposition of each compound. The modified films were characterized by cyclic voltammetry, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, and UV-Vis spectroscopy, confirming the formation of a mixture of HCMs in both methods of synthesis. Stability studies were evaluated in different supporting electrolytes, and composites presented good performances due to carbon nanotube stabilization. Electrochromic properties were also evaluated for selected composites, showing high electrochromic efficiency and stability. Graphical abstract ᅟ