Standards Development

Scope

This part of IEC 62607 establishes a standardized method to determine the key control characteristic

– Reduction level for GO and reduced GO (graphene-based material)

– Ultraviolet-visible spectroscopy (UV-VIS) and XPS technique

Purpose

Metallic van der Waals materials composed of a monolayer have recently drawn interest as a potential and adaptable application platform in a variety of industrial applications (electronics, optoelectronics, and energy storage devices). Because of its lower energy level, strong electrical and thermal conductivity, and high transparency due to its atomic thickness, graphene is among the most attractive possibilities for metallic van der Waals materials.

Chemical vapor deposition is a typical bottom-up approach, which is widely accepted as an effective synthetic method for producing monolayer graphene. The approach is very well suited for nano - structuring and obtaining superior monolayer graphene. However, to advance toward genuinely practical methods for commercialization, several issues still need to be addressed, such as the long synthesis time, high-temperature heat treatment, and the requirement for addi tional post-transfer- process, which limit the scalability and production of graphene. For the mass manufacturing of graphene, a solution-based direct reduction technique (top-down) has been taken into consideration.

Graphene oxide (GO) can be converted into graphene utilizing a variety of reducing substances and solutions. To perfectly replicate the remarkable properties of graphene, The degree of oxygen functionalization in GO needs to be lowered or eliminated. A subsequent GO transformation into reduced GO (rGO) can be done to induce the π-π conjugated structure. The determination of rGO‘s complete reduction and defect recovery, which includes lower oxygen concentrations, can show that GO/rGO restores some of graphene's industrially useful features, such as its good electrical and thermal conductivity.

This IEC Technical Specification provides a method for assessing the reduction level and surface composition of graphene-based material (particularly GO and reduced GO). The reduction level can be determined by UV-VIS spectroscopy (full width at half maxima (FWHM) and peak location) and X-ray photoelectron spectroscopy (XPS) spectroscopy (C/O ratios and deconvoluted spectra). Furthermore, the reduction of GO makes it very simple to produce rGO on a wide sca le in a variety of forms, such as suspensions or thin films, and it allows for the investigation of the degree of reduction of rGO on various media using UV-Vis and XPS specifications.