A review of the development of graphene material preparation via chemical approaches

Graphene nanomaterials have become the focus of scientific research and development activities due to unique physical and chemical properties. A widespread technique for the large-scale synthesis of graphene nanoparticles is referred to as "Hummer's" method. This process often produces hydrophilic functionalized graphene-based materials, referred to as graphene oxide (GO) and reduced graphene oxide (r-GO). It relies on the use of oxidation steps to achieve exfoliation of graphite micromaterials as raw resources to obtain graphite oxide also known as graphitic acid followed by further exfoliation techniques to attain GO materials. The different exfoliation degrees can be obtained by various standard amounts of chemical acids, which lead to different functional groups containing oxygen at various degrees of oxidation, which have effects on the electrochemical and physic-chemical characteristics. Understanding the structure of such graphite oxide has been involved in advancing the synthesis chemical methods, paving the way for the development of diverse graphene-based materials Therefore, the chemical synthesis progress based on Hummer's” approaches to prepare graphene nanomaterials have been reviewed. Also, development directions and the existing challenges are explained for pretreatment and surface functional modification for such nanomaterials.