Decarbonization of caffeine through an environmentally friendly carbon nanomaterial platform to address neurodegenerative diseases caused by emerging pollutants

Abstract

The current study focused on the synthesis and characterization of nitrogen-doped graphene quantum dots (NGQDs) and ozone-oxidized NGQDs (Oz-NGQDs) through a microwave-assisted method and subsequent ozone treatment. Structural results showed that the surface areas of NGQDs and Oz-NGQDs were determined to be 177 and 228 m²/g, and the average pore diameters for NGQDs and Oz-NGQDs were 14 and 27 nm, respectively, implying the amorphous nature imparted by the ozonation of the NGQDs. Study the optical properties showed band gap energies of 3.41 eV for NGQDs and 2.99 eV for Oz-NGQDs, demonstrating that Oz-NGQDs have a narrower band gap. Results of photoluminescence studies further indicated the promoted charge separation efficiency in Oz-NGQDs, with lower recombination rates and longer photo-induced electron lifetimes compared to NGQDs. Results of the photocatalytic studies exhibited remarkably higher CO₂ reduction activity of Oz-NGQDs compared to NGQDs, leading 70.29 µmol/gh CO production rate. The enhanced CO₂ adsorption and improvement charge separation efficiency on Oz-NGQDs was related to increased surface area, oxygen vacancies, and functional groups introduced by ozonation. Practical applicability was illustrated by the photocatalytic decarbonization of caffeine, reflecting the potential of Oz-NGQDs in environmental remediation and worthwhile chemistry applications.