A water stable cobalt-bipyridine based hydrogen bonding double layered network for catalytic degradation of tetracycline

• An environmental-friendly photocatalyst [Co(bipy)(H2O)4]BDC is prepared and characterized. • [Co(bipy)(H2O)4]BDC features photocatalysis-peroxymonosulfate (PMS) activation for tetracycline (TC) degradation. • [Co(bipy)(H2O)4]BDC has sufficient water stability and reusability. • Reactive species SO4•-, OH•, •O2−, and 1O2 are proposed in the photocatalytic process. Reaction of Co(NO 3 ) 2 ∙6H 2 O, 2, 2′-bipyridine (bipy) and 1, 4-benzene dicarboxylic acid (H 2 BDC) by a two-step hydrothermal process, a stable inorganic-organic hybrid compound, [Co(bipy)(H 2 O) 4 ]BDC ( 1 ), was obtained, which structure was characterized by X-ray single crystal diffraction analysis. Acted as catalyst, its photocatalysis-peroxymonosulfate (PMS) activation for tetracycline (TC) degradation was explored under solar light. The critical experimental factors in tetracycline decomposition were investigated, including the pH, [Co(bipy)(H 2 O) 4 ]BDC dosage, tetracycline concentration, PMS dose, and temperature. [Co(bipy)(H 2 O) 4 ]BDC has fast degradation performance, sufficient stability and reusability, that degradation rate were 97.5 % and 88.8 % after five cycles within 60 min. Furthermore, the sulfate radical (SO 4 •− , superoxide (O 2 •− ), hydroxyl (•OH) free radicals and singlet oxygen ( 1 O 2 ) were confirmed as the key oxidation factors in the 1 /PMS/SL system for tetracycline degradation. An environmental-friendly photocatalyst [Co(bipy)(H 2 O) 4 ]BDC is prepared and characterized. And this compound features photocatalysis-peroxymonosulfate activation for tetracycline degradation.