Insights into heterogeneous catalytic activation of peroxymonosulfate by Pd/g-C3N4: The role of superoxide radical and singlet oxygen

Abstract Pd nanoparticles anchored on graphitic nitride carbon (Pd/g-C 3 N 4 ) hybrid catalytic system was prepared by a simple KBH 4 reduction method. Pd/g-C 3 N 4 was very active in the degradation of bisphenol A (BPA) by efficiently activating peroxymonosulfate (PMS). Important influencing factors, such as catalyst dosage, PMS concentration, pH and reaction temperature for the BPA removal were investigated. Pd/g-C 3 N 4 -PMS demonstrated a wide effective pH range, namely 3.0–9.0. Radical quenching tests and electron spin response (ESR) analyses revealed that superoxide radical (O 2 − ) and singlet oxygen ( 1 O 2 ) instead of sulfate radical (SO 4 − ) and hydroxyl radicals ( OH) were the major oxidized species for the degradation of BPA.