Nest-like Co3O4 and PdO /Co3O4 synthesized via metal organic framework with cyclodextrin for catalytic removal of Bisphenol A by persulfate

In the present work, Co3O4 and PdOx/Co3O4 nanocrystals were obtained via the calcination of Hydroxypropyl-β-cyclodextrin (HP-β-CD) assistant-synthesized ZIF-67 and Pd(acac)2/ZIF-67, respectively. The results suggested that although the HP-β-CD was used during the preparation of ZIF-67 in the ethanol, it could be removed by washing the ZIF-67 for several times. The structure and composition of the Co3O4 and PdOx/Co3O4 prepared without and with the assistance of HP-β-CD were investigated. Finally, the results from the catalytic oxidation of Bisphenol A in the presence of potassium persulfate indicated that a better performance was observed over the HP-β-CD assistant synthesized Co3O4, possibly due to an increased specific surface area. In addition, it was found that a high oxidation state (IV) of Pd species in the PdOx/Co3O4 synthesized with the help of HP-β-CD was noticed compared with that synthesized without HP-β-CD. It was worth noting that the further catalytic tests suggested HP-β-CD assisted synthesized PdOx/Co3O4 displayed more than 2-fold higher activity compared with Co3O4 as well as PdOx/Co3O4, which was possibly ascribed to the better dispersion as well as the presence of Pd(IV) species, respectively.