A new Co-based complex using as a peroxymonosulfate activator for efficient degradation of Rhodamine B

Cobalt-based materials have been proved to be effective heterogeneous catalysts for the activation of peroxymonosulfate (PMS) to degrade many refractory organic dyes. Herein, a novel Co-based complex was prepared by hydrothermal method using py (pyridine) and pda (pyridine-2,3-dicarboxylic acid) as mixed ligands and Co(NO 3 ) 2 ·6H 2 O as Co 2+ ion source and characterized by techniques of Single-crystal X-ray diffraction (SC-XRD), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TG), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET). Then the prepared Co-based complex was utilized as a peroxymonosulfate (PSM) activator for the efficient degradation of Rhodamine B (Rh B). It was found that the degradation efficiency of Rh B by the system was as high as 98.34 % within 10 min. Meanwhile, the effects of Rh B concentration, catalyst dosage, PMS dosage, and reaction temperature on the degrading process were investigated. Free radical capture experiments confirmed that sulfate radical (SO 4 ˙ˉ) and hydroxyl radical ( ˙ OH ) were the main free radicals that played a role in the degradation of Rh B dye, and the possible degradation mechanism of the reaction was proposed. The recyclability test demonstrated that the catalytic efficiency of the prepared Co-based complex was still higher than 95 % after four cycles, and the characteristic peaks of PXRD spectrum match the simulated pattern. The present results indicated that the prepared Co-based complex can be serve as a stable and effective catalyst for generating free radicals (such as SO 4 • − , • OH) to further treat organic dyes and provide more options for future wastewater remediation.