Textural and electrochemical properties of carbon replica obtained from styryl organo-modified layered double hydroxide{
Résumé
Negative carbon replicas were obtained after pyrolysis of organo-modified layered double hydroxides (LDH) and dissolution of the inorganic moiety. The hybrid organic–inorganic precursors consisted of polystyrene sulfonate incorporated directly between LDH sheets of cationic composition Zn 2 Al or after in situ polymerisation of the monomers. The preparation conditions of the hybrid phase and the constraint imparted by the inorganic framework were found to affect strongly the textural properties. The carbons sequestered into the LDH intersheet gap present a textural hierarchy, i.e. a pronounced microporous character (micropore volume up to 1.07 mL g 21 and S BET = 2300 m 2 g 21) and a mesoporosity. The nanotexture of the carbon replica was characterized by Raman spectroscopy. Finally, the carbons tested by cyclic voltammetry and complex impedance spectroscopy in two-electrode electrochemical supercapacitors in sulfuric acid medium present a capacitive behavior, i.e. a quasi rectangular response of intensity versus potential and a phase angle in the Z0–Z9 impedance plane close to p/2.