Non-destructive covalent surface alkylation of graphitic carbon nitride for enhanced photocatalytic dye degradation in water

Graphitic carbon nitride (g-CN) is a promising material for various applications due to its unique electronic, optical, and photocatalytic properties, tunable by surface modifications. Herein, a novel and straightforward approach to the covalent addition of low molecular weight polyethylene glycol (PEG(550)) to g-CNs surface following non-destructive chemistry benefiting from simultaneous activation of hydroxyl and free-amine surface groups by a weak base, potassium carbonate, is for the first time described. The resulting g-CN-PEG(550) exhibits almost two-fold enhanced water solubility due to 1 PEG(550) chain addition for every similar to 128 g-CN atoms, detected by thermogravimetric analysis. Complementary X-ray photoelectron spectroscopy elemental analysis of the isolated g-CN-PEG(550) displays an increased C & horbar;O chemical environment attributed to the covalent addition of carbon- and oxygen-rich PEG(550) to the g-CN surface. The g-CN-PEG(550) photocatalyst performs 2.5-fold better in degrading rhodamine B due to its enhanced light absorption, improved water-dispersibility, and the efficient separation of photogenerated electron-hole pairs compared to the as-prepared g-CN. The study underscores the potential use of covalently PEGylated oxygen-rich g-CNs in photocatalytic applications.