4 research outputs found
Plasma Electrochemical Synthesis of Graphene-Phosphorene Composite and Its Catalytic Activity towards Hydrogen Evolution Reaction
For the first time, graphene-phosphorene structures were synthesized using the plasma-assisted electrochemical method. The catalytic activity of the composite obtained in the electrolytic plasma mode and its mixtures with few-layer graphene structures toward the hydrogen evolution reaction was studied. A substantial increase in the catalytic activity of the phosphorene structures towards the hydrogen evolution reaction was realized by mixing them with few-layer graphene structures. The catalyst demonstrates excellent activity towards the hydrogen evolution reaction in alkaline media with a low overpotential of 940 mV at a current density of 10 mA·cm−2 and a small Tafel slope of 130 mV dec−1
Plasma Electrochemical Synthesis of Graphene-Phosphorene Composite and Its Catalytic Activity towards Hydrogen Evolution Reaction
For the first time, graphene-phosphorene structures were synthesized using the plasma-assisted electrochemical method. The catalytic activity of the composite obtained in the electrolytic plasma mode and its mixtures with few-layer graphene structures toward the hydrogen evolution reaction was studied. A substantial increase in the catalytic activity of the phosphorene structures towards the hydrogen evolution reaction was realized by mixing them with few-layer graphene structures. The catalyst demonstrates excellent activity towards the hydrogen evolution reaction in alkaline media with a low overpotential of 940 mV at a current density of 10 mA·cm−2 and a small Tafel slope of 130 mV dec−1
Enhancement of the Carbon Nanowall Film Capacitance. Electron Transfer Kinetics on Functionalized Surfaces
The effects of electrochemical oxidation
and surfactant adsorption
on behavior of vertically oriented carbon-nanowall (CNW)-based electrodes
are studied. Electrochemical oxidation is carried out by the electrode
polarization in aqueous solutions at high anodic potentials corresponding
to water electrolysis, whereas the modification of surface by surfactants
is accomplished by the adsorption of molecules characterized by the
cage-like structure. Using the methods of cyclic voltammetry and impedancemetry,
it is shown that a substantial increase in the capacitance of CNW-based
electrodes is observed in both cases (30–50-fold and 3–5-fold,
respectively). The as-grown and modified electrodes are characterized
by scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron
spectroscopy. A substantial increase in a number of oxygen-containing
functional groups is observed on the CNW surface after the electrode
polarization at high anodic potentials. The kinetics of redox reactions
on the CNW film surface is studied by comparing the behavior of systems
[RuÂ(NH<sub>3</sub>)<sub>6</sub>]<sup>2+/3+</sup>, [FeÂ(CN)<sub>6</sub>]<sup>4–/3–</sup>, Fe<sup>2+/3+</sup>, and VO<sub>3</sub><sup>–</sup>/VO<sup>2+</sup>. It is demonstrated that oxidation
of nanowalls makes the electron transfer in the redox reaction VO<sub>3</sub><sup>–</sup>/VO<sup>2+</sup> and the redox system Fe<sup>2+/3+</sup> considerably easier due to coordination of discharging
ions of these systems with the functional groups; however, no such
effect is observed for the redox-systems [FeÂ(CN)<sub>6</sub>]<sup>3–/4–</sup> and [RuÂ(NH<sub>3</sub>)<sub>6</sub>]<sup>2+/3+</sup>