Multifaceted graphene-based materials for comprehensive environmental sustainability

Graphite (Gt) derived graphene (Gr) and its exceptional mechanical strength, thermal conductivity and electrical properties make it a revolutionary material for 21st-century environmental technologies. This review focuses on the synthesis, functionalization and environmental remediation of graphene oxide (GO), reduced graphene oxide (rGO) and their derivatives for wastewater purification, pollutants adsorption, catalysis and sensing applications under controlled pH, temperature, and ionic strength. Hydrophilic surface of GO with oxygen functionalities enables strong electrostatic interactions with neonicotinoids of adsorption capacities 3.11 mg/g, ciprofloxacin of 500 mg/g, Zn(II) of 345 mg/g and Methylene blue of 450 mg/g for removing cationic impurities. Also, rGO efficiently removes cationic pollutants such as As(III), As(V) and Cr(VI), while functionalized graphene aerogel (fGA) shows recyclability along with improved oil, dyes and solvent adsorption. The microalgae Galdieria sulphuraria achieved 71 % COD, 80 % BOD and 66 % FOG reduction in restaurants’ wastewater with significant nutrient uptake of 96 % NH 4 + -N and 99 % TP removal which highlights bio-integrated remediation potential. Photocatalysts GO-TiO 2 and Ni-GO composites examined improved hydrogen evolution up to sevenfold, while rGO-TiO 2 photocatalyst generate reactive oxygen species for pollutants mineralization. Gr-based electrochemical sensors detect Hg 2+ as low as 0.6 nM and Pb 2+ at 5ppb, demonstrating ultrahigh sensitivity. So, Gr-based nanocomposites offer sustainable sensing, though scalable green synthesis. However, safety regulations remain essential for large-scale deployment. Multifaceted graphene-based materials: A platform for comprehensive environmental sustainability • Graphene-based nanomaterials for diverse pollutants removal. • Improved water purification selectivity of graphene composites with polymers and metals. • Toxicity, scalability, and regulatory needs for future sustainable practical deployment. • A promising multifunctional platform for sustainable environmental remediation.