Effect of Precursor and Exfoliation on the Photocatalytic Performance of g-C₃N₄ Toward Pharmaceutical Contaminants

The increasing consumption of pharmaceuticals and their continuous release into aquatic environments have raised significant environmental concerns. Even at low concentrations, these contaminants can negatively impact ecosystems and human health. Conventional wastewater treatment plants (WWTPs) are often insufficient for their complete removal, emphasizing the need for more advanced treatment solutions. Among advanced oxidation processes (AOPs), heterogeneous photocatalysis has shown promise for the efficient degradation of various pharmaceutical compounds, including antibiotics, analgesics, anti-inflammatory drugs, and anesthetics. Graphitic carbon nitride (g-C₃N₄), a polymeric, metal-free semiconductor composed primarily of carbon and nitrogen, is a promising material for visible-light-driven photocatalysis. In this study, g-C₃N₄ was synthesized via thermal polymerization using urea and melamine as nitrogen-rich precursors. The materials were subsequently exfoliated to improve their surface area and enhance photocatalytic activity. The prepared samples were characterized using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) to determine bonding environments and crystal structure. Brunauer–Emmett–Teller (BET) surface area analysis was used to evaluate textural properties, and diffuse reflectance spectroscopy (DRS) was employed to estimate the optical band gap. The adsorption behavior and photocatalytic degradation of procaine, a local anesthetic, were studied under UV-A light and simulated solar irradiation in a batch reactor. Preliminary results suggest that exfoliated g-C₃N₄ synthesized from urea exhibits improved photocatalytic performance compared to other variants, likely due to its higher surface area. While full comparative testing is ongoing, these findings indicate that urea-derived, exfoliated g-C₃N₄ is a promising candidate for solar-driven degradation of pharmaceutical pollutants.