Degradation of Lignin Pollutants by Persulfate Activated with a Graphene Oxide Loaded Cu₂(OH)₃NO₃ Composite

Graphene oxide (GO)-Cu₂(OH)₃NO₃ composite was prepared by a thermal calcination process and evaluated as an effective heterogeneous catalytic material. The composite displayed prominent activated performance to persulfate, which was influenced by preparation condition and the reaction parameters in catalytic system. Under optimal reactive conditions, the GO-Cu₂(OH)₃NO₃ composite yielded rapid degradation of ferulic acid, which the corresponding apparent rate constant was 1.12×10⁻¹ min⁻¹. Catalytic mechanism analysis showed that the main oxygen species were ⋅SO₄⁻ and ⋅OH. Among them, ⋅OH made the main contribution in the catalytic system. The analysis of degradation intermediates of ferulic acid showed that the compound could be mineralized to small molecules. The remarkable enhanced heterogeneous catalytic performance of GO-Cu₂(OH)₃NO₃ was due to a larger specific surface area, high adsorption capacity and a high mass transfer efficiency of oxidizing radicals in the reactive system.