Catalytic degradation of anthraquinones-containing H2O2 production effluent over layered Co-Cu hydroxides: Defects facilitating hydroxyl radicals generation

Anthraquinones from H2O2 production effluent (AHE) was remediated over a Co-Cu Layered Double Hydroxide (LDH) through a Fenton-like reaction process. The variation of synthesis pH value has found to significantly influence the catalyst performances for hydroxyl radical generation. Defects (oxygen vacancies) in the catalyst surface which facilitates H2O2 decomposition was systematically studied with adjusting the synthesis pH value. The framework of catalyst with LDH feature was thoroughly characterized by several spectroscopy techniques. The formation of Co-O-Cu oxo-bridged bond is assumed to be responsible for the electron transfer and the generation of defects. However, the surface electronic structure was altered with the changes in Co and Cu contents. The defect-rich LDH framework with abundant defects (oxygen vacancies) promote electron transfer, and H2O2 dissociation are primarily to account for the excellent catalytic performance. The application of this catalyst and its optimization of operational parameters in AHE removal were thoroughly performed as well.