Heterogeneous catalysts have ignited an attraction in the field of energy and environmental concerns in recent years. Its potential applications are being addressed both globally and cost-effectively. Functionalization of graphene oxide (GO), with chemically active groups that can accept oxygen, is gaining the researchers’ attention because of its exceptional features like extensive surface area, mechanical stability and variable optical and electrical characteristics. GO is also a magnificent applicant for coordination with other substances and molecules with presence of its terminal chemical groups such as hydroxyl, epoxy and carboxyl. As a result of expansion of structural diversity, the graphene-based nanocomposites have become a new research hotspot, especially in the energy storage and environmental protection field. An overview is provided in this analysis for both the structure and characteristics of the GO/rGO-related materials used in various energy (photovoltaic and photoelectrochemical devices/electrochemical devices) and environmental applications (dye removal and CO<inf>2</inf> reduction). A new path towards the development of incredibly effective graphene/GO/rGO -based nanocomposites for heterogeneous photocatalytic and energy applications may become evident by investigating the many features of 2D graphene and graphene oxide. An extensive conclusion is also provided at the end of the article, detailing the fascinating research activities with GO/rGO based nano composites and their utilisation for energy storage and the environment remediation. © 2024 Elsevier B.V., All rights reserved.