Comprehensive review on synthetic methods and functionalization of graphene oxide: Emerging Applications

Graphene oxide (GO) is a unique and versatile material derived from graphene, which is a single layer of carbon atoms arranged in a hexagonal lattice. Functionalized graphene oxide refers to GO that has undergone further chemical modifications by attaching specific functional groups or molecules to its surface. This process imparts exceptional optical, electronic, thermal, magnetic, and mechanical characteristics, in addition to a substantial specific surface area and various functionalities to the material broadening its scope for potential applications. With an eye on the evolving demands of future materials, this review comprehensively outlines the synthesis of GO through diverse techniques, encompassing mechanical, chemical, and electrochemical exfoliation along with reduced GO and chemical vapour deposition approaches. Additionally, we delve into the synthesis of GO functionalized (fGO) with diverse functional groups using various methods, including chemical and covalent modification; addition, cycloaddition, electrophilic, nucleophilic and esterification; and condensation. fGO finds applications in diverse areas, all of which are explored in this work, including energy storage, sensors, catalysis, drug delivery, nanocomposites, biosensors, and environmental remediation. These findings undoubtedly pave the path for the creation of innovative synthetic nanocomposites through surface modification, expanding their potential for versatile applications. [Display omitted] •Exploration of graphene oxide synthesis via mechanical, chemical, electrical exfoliation, and chemical vapor deposition.•Synthesis of functionalized graphene oxide (fGO) with diverse functional groups.•Routes to covalently modify GO, including nucleophilic and electrophilic substitution, condensation, and addition.•Elaborated structure and properties of graphene oxide and its derivatives.•Applications of fGO in diverse areas, including energy storage, environmental remediation, and optoelectronics.