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Electrochemical CO2 reduction has drawn substantial attention not only due to the demand for energy but also the need for a sustainable environment. In this work, a non-noble based electrocatalyst (Cu2O-MoS2) was developed using a facile method for its application in CO2 reduction. The synthesized composite material was characterized using XPS, XRD, FTIR, Raman, FESEM and EDS. The Cu2O-MoS2 composite material presented outstanding electrocatalytic activity towards CO2 reduction, and showed a reducing current density of 113 mA/cm2-almost twice that of the bare Cu2O (61 mA/cm2) and eight times higher than that of MoS2 sheet (21.3 mA/cm2). Furthermore, the onset potential of the Cu2O-MoS2 composite material is much lower compared to bare Cu2O nanoparticles and MoS2 sheets. The faradaic efficiency of the Cu2O-MoS2 composite material depends on the applied potential and it was found to be 12.3% and 7.9% for methanol and ethanol at − 1.3 V and − 1.1 V, respectively. [ABSTRACT FROM AUTHOR]

Thanks to their high power density and degree of reversibility, supercapacitors are electrochemical devices that narrow the gap between secondary batteries and traditional dielectric capacitors in the traditional Ragone plot. However, their use is still hindered by their capability to achieve higher energy density. In this work, we present a one-pot synthesis procedure of composite graphitic carbon flake-supported NiO for electrochemical energy storage application. We used cathodic contact glow discharge electrolysis by applying 120 Vdc terminal voltage between a thin Pt wire, slightly submerged in an aqueous solution of NiSO4(H2O)6 + Na2SO4, and a large surface area carbon graphite anode. Strong active species generated within the micro-plasma volume locally reduce the nickel precursors to form NiO materials, while at the anodically polarized graphite rod, the forces holding the graphene layers together are weakened by ion/solvent intercalation producing micrometer-sized graphitic carbon flakes. The morphological characterization is carried out by electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and micro-Raman spectroscopy. Cyclic voltammetry, constant-current charge/discharge, and electrochemical impedance spectroscopy in 5 mol l−1 KOH solution are carried out to evaluate the electrochemical energy storage performance of the material. We show that carbon flake-supported NiO exhibits the dual combination of electric double-layer capacitance with faradic behavior, giving 495 F g−1 specific capacitance at 2 A g−1 current density. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO 2 with high selectivity for alcohol production has been considered as a proper way to address both energy catastrophe and environmental complications around the globe. Herein, two metal oxides, namely CuO and ZnO having great potential to catalyze the CO 2 reduction, are chosen to form a composite with MoS 2 , where MoS 2 sheets act as support and enhance electrocatalytic properties of CuO–ZnO due to their synergistic effect. The synthesis and characterizations of the tricomponent CuO–ZnO–MoS 2 composite material is reported for the first time in this work. The composite possessed outstanding catalytic performance in CO 2 reduction to alcohol in terms of extraordinary current density (121 mA/cm2) and low onset potential (−0.23 V vs RHE). The composite material showed maximum faradaic efficiency of 24.6% and 11.1% for methanol and ethanol at −0.6 V and −0.9 V vs RHE, respectively. [Display omitted] • A novel tricomponent composite (CuO–ZnO–MoS 2) material was developed. • The synthesized material was characterized by different instrument techniques. • The composite possessed excellent catalytic activity in CO 2 reduction. • Faradaic efficiency of 24.6% and 11.1% for methanol and ethanol was achieved. [ABSTRACT FROM AUTHOR]