Non-templated ambient nanoperforation of graphene: a novel scalable process and its exploitation for energy and environmental applications

Abstract

Nano-perforation of 2D graphene sheets is a recent and strategically significant means to exploit such materials in modern applications such as energy production and storage. However, current options for the synthesis of holey graphene (hG) through nano-perforation of graphene involve industrially undesirable steps viz., usage of expensive/noble metal or silica nanoparticle templates and/or hazardous chemicals. This severely hampers its scope for large scale production and further exploitation. Herein, we report for the first time a scalable non-templated route to produce hG at ambient conditions. Nano-perforation is achieved with tunable pore size via the simple few layer co-assembly of silicate-surfactant admicelles along the surface of graphene oxide. A gentle alkali treatment and a reduction at optimized conditions readily yielded holey graphene with a remarkable capacitance (∼250 F g(-1)) and interesting adsorption abilities for pollutants. Density functional theory based computational studies reveal interesting insights on the template free nano-perforation at a molecular level. This simple rapid process not only excludes the need for expensive templates and harmful chemicals to yield hG at attractively ambient, chemically placid and industrially safer conditions, but also creates no hurdles in terms of scaling up.

Holey graphene: a unique structural derivative of graphene

“…Threedimensional porous structures were also found in the final hG products, which exhibited somewhat lower BET surface area values ( ∼ 800 m 2 /g) than typical a-MEGO materials. Room temperature etching with aqueous NaOH solution was successful with silica-coated GO [70]. The treatment with NaOH not only removed the silica coating, but also simultaneously caused perforation of the graphene sheet.…”

Exploring Battery‐Type ZnO/ZnFe2O4 Spheres‐3D Graphene Electrodes for Supercapacitor Applications: Advantage of Yolk−Shell over Solid Structures

“…The enlarged interlayer distance compared to pristine graphite (3.36 Å) is ascribed to the introduction of oxygen-containing functional groups on to the surface of graphitic layers due to oxidation. [28] Likewise; the interlayer distance of GH is lower compared to that of graphene oxide, indicating partial removal of the oxide functional groups from GO sheets during the hydrothermal process. The characteristic peak at 26.5°of the graphitic structure appears broader and slightly shifted to left in the case of GH, due to the partial recovery of π-conjugated graphene sheets from the original highly oxidized GO sheets.…”

“…The 002 plane of GO with a d ‐spacing of 8.21 Å appears as a sharp peak at a 2θ=10.76° as shown in Figure a. The enlarged interlayer distance compared to pristine graphite (3.36 Å) is ascribed to the introduction of oxygen‐containing functional groups on to the surface of graphitic layers due to oxidation . Likewise; the interlayer distance of GH is lower compared to that of graphene oxide, indicating partial removal of the oxide functional groups from GO sheets during the hydrothermal process.…”

The Influence of Hydrogen Passivation on Conductive Properties of Graphene Nanomesh—Prospect Material for Carbon Nanotubes Growing

“…It combines outstanding properties of graphene and unique physical and chemical properties determined by the edge atoms around nanoholes [1,2]. In recent years, many strategies of GNM synthesis have been developed: solvothermal reaction [3], nontemplated synthesis [4], self-templated synthesis [5], single-step air oxidation process [6], etc. [7].…”

“…The density functional theory (DFT) calculations established that a BG of GNM passivated by hydrogen varied in the range of 0.35-0.95 eV in dependence on a nanohole's size and hydrogen concentration [13]. Though the influence of the neck's width on the conductive properties of GNM were estimated [4], the influence of hydrogen passivation isn't defined yet. To our mind, this research could significantly enlarge GNM knowledge and expand an area of GNM application.…”