Selective Catalytic Electro-Oxidation of Water with Cobalt Oxide in Ion Impermeable Reduced Graphene Oxide Porous Electrodes.

The direct electrolysis of seawater is greatly inhibited by the oxidation of Cl to free chlorine, an undesirable, corrosive byproduct. To suppress the parasitic interference of Cl and any other ion, we developed a freestanding, electrically conducting, 3D macroporous reduced graphene oxide (rGO) scaffold with cobalt oxide particles selectively deposited on the internal walls of its closed pores (with an average diameter of ∼180 μm). The pore walls act as membranes composed of stacked rGO flakes; the nanochannels between rGO layers (size <1 nm) are permeable to water and gases while preventing the diffusion of dissolved ions such as Cl.

Non-purified commercial multiwalled carbon nanotubes supported on electrospun polyacrylonitrile@polypyrrole nanofibers as photocatalysts for water decontamination.

We present a photoactive composite material for water decontamination consisting of non-purified commercial multiwalled carbon nanotubes (CNT(NP)s) supported on an electrospun polymeric mat made of core-sheath polyacrylonitrile-polypyrrole nanofibers. This is the first system that specifically exploits the superior photocatalytic activity of CNT(NP)s compared with the purified carbon nanotubes usually employed. A CNT(NP) still contains the catalytic metal oxide nanoparticles (NPs) used for its synthesis, embedded in the nanotube structure.