Degradation of ofloxacin by peroxymonosulfate activated with cobalt-doped graphitic carbon nitride: Mechanism and performance

•Co doped g-C3N4 (CoCN) catalysts were prepared via the facile thermal condensation protocol to degrade ofloxacin.•Compared with the CN sample, CoCNx could effectively activate PMS to degrade OFX.•The degradation efficiency of CoCN10/PMS system was desirable and with wide pH tolerance.•Sulfate radical was the main active species in CoCN10 /PMS system.