Noble metal -doped graphitic carbon nitride photocatalyst for enhancement photocatalytic decomposition of antibiotic pollutant in wastewater under visible light

This study the noble metal (Ag)-doped graphitic carbon nitride (g-C3N4) photocatalyst was synthesized via a facial thermal condensation method. The structure and surface elements distribution of synthesized materials were characterized using XRD, SEM, XPS, UV-vis and N-2 adsorption-desorption experiment. The doping of Ag not only decreased the band-gap energy and particle size, but also enhanced the separation of charge carriers and decreased the electron/hole recombination in the g-C3N4 structure. The photocatalytic activity of Ag-doped g-C3N4 was investigated using oxytetracycline (OTC) as a model pollutant. The loading of 7% Ag onto g-C3N4 showed highest photocatalytic degradation efficiency of OT. The synthesized photocatalyst showed extremely high stability after 5 cycles as confirmed through various characterization techniques such as SEM and XRD. Eventually, several degradation intermediates of OTC were identified, and possible decomposition pathways were proposed. The 7-AgCN also was applied for the degradation of complex antibiotic wastewater, the removal efficiencies of OTC within 120 min was 98.7%. Overall, this work provides a novel strategy for the green synthesis of Ag-supportedg-C3N4, and its promising application prospect in environmental remediation.