Advancements in GO-Polymer Nanocomposites: A Paradigm Shift in Energy Harvesting and Sensor Engineering

Graphene derivatives, i.e., graphene oxide (GO) and reduced graphene oxide (rGO), have emerged as unparalleled nanofillers for the development of advanced polymer nanocomposites (PNCs), owing to their unique combination of high specific surface area, tunable surface chemistry, mechanical robustness, and exceptional electrical conductivity. These attributes enable strong interfacial interactions with polymer matrices, resulting in synergistic enhancements in structural, functional, and electrochemical performance. This Review presents a comprehensive and critical overview of the synthesis strategies of GO and rGO, including top-down and bottom-up approaches, with particular emphasis on scalability, reproducibility, and cost-effectiveness for large-scale production. The integration of GO/rGO into polymer systems is systematically discussed, highlighting the roles of surface functionalization, dispersion strategies, and interfacial engineering in achieving high performance. In addition, the pivotal role of GO/rGO-based PNCs in next-generation energy storage and conversion technologies is explored, where enhanced charge transport, improved electrochemical stability, and increased active surface area contribute to superior device performance. In addition, emerging applications of these nanocomposites in sensing platforms are critically examined, particularly for the detection of chemical and environmental pollutants with high sensitivity and selectivity. Mechanistic insights into signal transduction and analyte interaction are also discussed. Finally, key challenges related to scalability, long-term stability, and environmental impact are addressed, along with future perspectives for the rational design of multifunctional GO/rGO-based polymer nanocomposites.