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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]

Abstract: A conjugated oligomer containing central bi-ethylenedioxythiophene (BEDOT) unit and two terminal anil-substituted carbazole units has been characterized by cyclic voltammetry and spectroelectrochemical methods (UV–vis–NIR and Raman). It shows two oxidation waves at −0.01V and +0.24V (versus Fc/Fc+), which can be ascribed to two successive oxidative dopings of the molecule. The molecule is transmissive sharp yellow when fully reduced, transmissive green upon oxidation up to the end of the first oxidative process, and dark blue upon full oxidation. UV–vis–NIR and Raman spectroelectrochemical investigations show that the colour changes within the potential of the first oxidation wave are associated with the oxidation of both carbazole and ethylenedioxythiophene subunits whereas the electrochromic effect in the potential range of the second oxidation wave involves predominantly the oxidation of the ethylenedioxythiophene subunits. [Copyright &y& Elsevier]

Abstract: Highly doped (both n and p-type dopings) silicon nanowires (SiNWs) have been deposited via Chemical Vapor Deposition and investigated as electrode materials for micro-capacitor in a standard organic based electrolyte. Silicon nanostructuration enables to increase areal capacitance. Double layer capacitance values up to 46μF·cm−2 have been measured. Micro capacitors based on two SiNWs electrodes exhibit an excellent cycling ability and power density as high as 1.6mW·cm−2. [Copyright &y& Elsevier]