In this study, Me-doped g-C 3 N 4 (Me = Cu, Co and Fe) catalysts with various % w/w of Me dopant are prepared by a versatile calcination protocol for catalytic redox-based advanced oxidation process. The characterization study using FESEM, EDX, TEM, XRD, TGA, XPS, FTIR and BET indicates that all the Me-doped g-C 3 N 4 consist of irregular morphology with at least 1.4–1.9 times higher surface area than that of pristine g-C 3 N 4 . The catalysts were used to generate SO 4 − from peroxymonosulfate (PMS) for selective sulfathiazole (STZ) degradation. The results show that the catalytic activities of the Me-doped g-C 3 N 4 are in the following order: Co-doped g-C 3 N 4 (0.59% w/w Co, Co–g–4) > Fe–doped g-C 3 N 4 ≫ Cu-doped g-C 3 N 4 ∼ pristine g-C 3 N 4 . The excessive Me doping have a negative effect on catalytic performance due to the undesired SO 4 − scavenging by surface defects (–C N) and excess Me. The STZ degradation were highly influenced by the pH, catalyst loading and Oxone® dosage. The predominant reactive radical is identified to be SO 4 − which contributes to >82% of total STZ degradation. The LC/MS/MS system was used to confirm the selectivity of SO 4 − for STZ degradation. The main STZ degradation pathway is also proposed. The performance of Co–g–4/PMS system for STZ removal in the treated drinking water (TW) and secondary wastewater effluent (SE) was investigated. It is found that, despite having poorer performance compared with the DI water due to the presence of various water matrix species particularly the dissolved organic matter, the selectivity of SO 4 − for STZ in SE and TW is evidenced. Overall, the Co-g-4/PMS system shows promising performance and excellent stability for selective catalytic degradation of sulfonamide antibiotics in water. [ABSTRACT FROM AUTHOR]