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Highlights • Vertical silicon, diamond and graphene structures for supercapacitor applications. • Electrochemical synthesis of conducting polymers onto 3D nanostructures. • Electrochemical performances of supercapacitor devices using ionic liquids. • Multi-hierarchized 3D nanostructures (PEDOT-D@SiNWs) showed the best performances. • Supercapacitive graphene and diamond nanostructures for new perspectives using ILs. Abstract The potential of electroactive conducting polymers (ECPs), as innovative pseudocapacitive materials, has recently emerged as a promising strategy to design new and advanced concepts in the field of electrochemical energy storage devices. From this point of view, the synergistic effect produced between high electroactivity ECPs (faradaic behaviour) and large active surface 3D nanostructured materials (electrochemical double layer behaviour) in terms of their high specific capacitance, high energy and power density as well as long lifetime, has awakened an enormous interest in the domain of (micro)-supercapacitors. Accordingly, in this work, we have originally analyzed the conformal electrochemical deposition of three different π-conjugated heterocyclic polymers [poly(3,4-ethylenedioxythiophene, polypyrrole and polyaniline] onto various vertically-oriented 3D nanoarchitectures, as for example silicon nanowires (SiNWs), diamond nanowires (DiNWs) or graphene nanosheets (GNs) among others. Next, the resulting as-grown hybrid materials were evaluated as attractive electrodes in symmetric supercapacitors (sandwich configuration) in presence of organic, aqueous, aprotic and protic ionic liquid (IL) electrolytes respectively. An exhaustive characterization of their corresponding electrochemical performances was investigated according to our previously reported works, confirming the remarkable cycling stability of ECPs in ILs. In addition, a detailed state-of-the-art dealing with other types of (micro)-supercapacitors in the literature was reported to corroborate the great impact of such devices to pave the way towards the elaboration of next generation high performance supercapacitors in the coming years. [ABSTRACT FROM AUTHOR]

N-Ethylcarbazole (NECZ) or carbazole (CZ) and bithiophene (BT) have been used as a mixture of monomers for the formation of electrodeposited polymer and copolymer films on platinum electrode. When beginning with a NECZ–BT mixture, the peak intensity resulting from the composite film cycling decreases with increasing initial NECZ proportion until that proportion reaches 40%. For higher NECZ proportions, no deposit could be obtained. Infrared spectra of the deposits show the presence of the characteristic bands of both monomer units in the material. In the case of CZ–BT mixtures, the electrochemical behaviours of the composite films are close to those displayed by the homopolymers, i.e. polybithiophene or dicarbazyle, containing respectively low and high proportions of CZ. Furthermore, infrared and ultraviolet-visible studies of deposits obtained for various CZ proportions yield spectra that vary according to monomer proportion. [Copyright &y& Elsevier]