Comprehensive overview of graphene synthesis, properties, and multifaceted applications for a sustainable future

Graphene has garnered enormous interest due to its unique combination of properties, including ultra-high electron mobility (200000 cm 2 V −1 s −1 ), superior electrical (∼1000000 S cm −1 ), thermal (∼5300 W m −1 K −1 ) conductivity, and mechanical strength (∼1000 GPa), as well as a huge specific surface area (∼2630 m 2 g −1 ). This review focuses on various synthetic methodologies, functionalization techniques, and diverse applications of graphene. The major synthetic routes, top-down methods (mechanical exfoliation, liquid-phase exfoliation, electrochemical exfoliation, chemical synthesis, and chemical exfoliation), and bottom-up approaches (chemical vapour deposition, pyrolysis, and epitaxial growth) are systematically evaluated and discussed. Functionalization enhances the physical and chemical properties of graphene, improving its dispersibility and facilitating targeted binding with specific molecules, thereby expanding its applications in sensitive sensors, robust battery electrodes, super-capacitors, and flexible electronics. The use of graphene in solar cells results in improved power conversion efficiency (up to 25.9%) compared to traditional cells (10–15%). Further, the biocompatibility of graphene opens a wide array of medical applications. Graphene-based materials hold sufficient potential, which may pave the way for an innovative, efficient, and sustainable future. • Various methods for synthesizing and functionalizing graphene. • Surface modifications and functionalization enhance the properties of graphene. • Applications of graphene in biomedical, electronics, energy storage, catalysis, and photovoltaic cells.