Unlocking Graphene Functionalization: Synthesis of Photo- and Redox-Active Pyrene Derivatives for Advanced Energy Storage and Optoelectronic Applications

Doctoral thesis, 2025

The unique properties of two-dimensional (2D) materials, particularly graphene, have garnered significant research interest across various interdisciplinary fields and hold promise for applications in areas such as field-effect transistors, biological systems, water purification, and energy storage devices. Functionalizing graphene mitigates its tendency to reaggregate, while introducing functional groups imparts new properties, effectively expanding the range of its applications. It has proven to be a powerful strategy for enhancing graphene's versatility and potential across diverse technological domains.

The extensive use of fossil fuels has led to significant environmental challenges and raised concerns over the depletion of fossil energy resources, highlighting the urgent need for sustainable alternative energy sources. Lithium-ion batteries (LIBs), widely used as primary energy storage devices in daily life, offer the advantage of high energy density. However, their application in large-scale energy storage is constrained by limitations in power density, safety concerns, and reliance on finite resources. Aqueous supercapacitors incorporating 2D materials present a promising solution to these challenges. In this thesis, we have developed aqueous supercapacitors using pyrenetetraone derivative-functionalized graphene as cathode materials and thermal treated Ti3C2Tx as the anode material. The as-assembled supercapacitor can deliver an excellent energy density of 38.1 Wh kg-1 at a power density of 950 W kg-1. Moreover, various spectroscopic analyses reveal distinct interaction behaviors among differently functionalized 2D materials, offering valuable insights for the development of organic-based electrode materials.

In addition, donor-acceptor (D-A) systems based on pyrenetetraone derivatives have been designed and synthesized for the noncovalent functionalization of graphene. The interaction between the D-A molecules and graphene was studied using different characterization techniques. The structure–property relationship in the nonlinear optical response of the hybrids will be further explored.