Carbon composites and replicas from intercalated layered double hydroxides

Carbon composites and replicas were prepared from layered double hydroxide (organo-LDH) intercalated with carbon 3-sulfopropylmethacrylic acid (SPMA). After intercalation, the organo-LDHs were calcined and acid-leached. Carbonization and acid-leaching were followed by in situ XRD, Raman spectroscopy, and observed by scanning electron microscopy. The pore formation in the carbon replica was studied by nitrogen adsorption. Electrochemical processes were studied by varying the potential scan rate, and the Faraday contribution was evaluated. The electrochemical impedance spectroscopy of the carbon composite indicated the conductivity and embedded inorganic redox centers. In comparison, carbon from SPMA had a capacitance as high as 280 F/g in aqueous Na2SO3 solution corresponding to an electric energy of 47.5 W h kg−1 and a power density of 17.3 kW kg−1 (ΔV = 1.1 V at 2 mV s−1). These properties were explained on the basis of electrochemically fully exposed surfaces as well as large amounts of oxygen surface groups.