Design of a Prussian Blue Analogue/Carbon Nanotube Thin‐Film Nanocomposite: Tailored Precursor Preparation,Synthesis, Characterization,and Application

Multi‐walled carbon nanotubes (MWCNTs) filled with different species of cobalt (metallic cobalt, cobalt oxide) were synthesized by a chemical vapor deposition method through cobaltocene pyrolysis. A systematic study was performed to correlate different experimental conditions with the structure and characteristics of the obtained material. Thin films of Co‐filled CNTs were deposited over conductive substrates through a liquid–liquid interfacial method and were used for cobalt hexacyanoferrate (CoHCFe) electrodeposition by an innovative route in which the Co species encapsulated in the CNTs were employed as reactants. The CNT/CoHCFe films were characterized by different spectroscopic, microscopic, and electrochemical techniques and presented high electrochemical stability in different media. The nanocomposites were applied as both an electrochemical sensor to H₂O₂ and a cathode for ion batteries and showed limits of detection at approximately 3.7 nmol L ^?1 and a capacity of 130 mAh g^?1 at a current density of 5 A g^?1.