Enhanced photocatalytic efficiency in C3N4 via particle and surface engineering of Graphene quantum dots

Graphene quantum dots (GQDs) have been employed to enhance the photocatalytic performance of carbon nitride (C₃N₄), leveraging their superior physicochemical characteristics. The photovoltaic attributes of GQDs, influenced by their particle sizes and surface states, are contingent upon their synthesis methods. This research focused on the synthesis of GQDs with diverse particle sizes and surface features by modifying carbon nanotubes (CNTs) using HNO₃. The findings indicate that prolonging the reaction time decreases the size of GQD particles and augments the presence of surface functional groups. Upon forming heterojunctions with C₃N₄, the GQDs-96/HC₃N₄ composite showcased superior photocatalytic degradation performance towards tetracycline hydrochloride (TC) and methyl orange (MO). This enhancement is attributed to the improved dispersibility and oxygen-containing functional groups of GQDs-96, facilitating effective interaction with HC₃N₄. This research provides a new guideline and idea for regulating the particle size and surface state of GQDs for their application in enhancing the photocatalytic performance of C₃N₄ for the degradation of water pollutants.