Photo-Fenton degradation of multiple pharmaceuticals at low concentrations via Cu-doped-graphitic carbon nitride (g-C₃N₄) under simulated solar irradiation at a wide pH range

A large variety of pharmaceuticals and personal care products (PPCPs) have been detected in water which makes it imperative to explore new materials for their efficient removal. In this study, the photo-Fenton degradation of pharmaceuticals has been investigated systematically via in situ synthesized Cu-doped g-C3N4. Detailed photoelectrochemical measurements confirm that the adsorption edges of modified g-C3N4 show a remarkable shift (Band gaps decreased from 2.79 eV to 2.17 eV), indicating the advantages of solar light absorption. Three major reactive radicals were identified, including •OH, 1O2, and -O2. The sulfadimethoxine (SMT) was degraded completely (> 99 %) at a wide pH range from 4 to 8. A total of 16 micropollutants, including anti-inflammatory, quinolone, and macrolide, were spiked with low concentration (100 μg/L) in simulated water, which can be removed rapidly within only 3 min. To make separating and reusing easy, the powder was successfully loaded onto a PTFE (Poly tetra fluoroethylene) support (0.22 μm) with a loading amount of 1.29 mg/cm2. The pharmaceutical can be effectively degraded without obviously losing the active properties under simulated solar irradiation.