Activation of peroxymonosulfate by metal (Fe, Mn, Cu and Ni) doping ordered mesoporous Co₃O₄ for the degradation of enrofloxacin

Abstract

Various transition metals (Fe, Mn, Cu and Ni) were doped into ordered mesoporous Co 3 O 4 to synthesize Co 3 O 4 -composite spinels. Their formation was evidenced by transmission electronic microscopy (TEM), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis. It was found that Co 3 O 4 -composite spinels could efficiently activate peroxymonosulfate (PMS) to remove enrofloxacin (ENR) and the catalytic activity followed the order Co . Moreover, through the calculation of the specific apparent rate constant (k sapp ), it can be proved that the Co and Cu ions had the best synergistic effect for PMS activation. The Co 3 O 4 -composite spinels presented a wide pH range for the activation of PMS, but strong acidic and alkaline conditions were detrimental to ENR removal. Higher reaction temperature could promote the PMS activation process. Sulfate radical was identified as the dominating reactive species in Co 3 O 4 -composite spinel/ PMS systems through radical quenching experiments. Meanwhile, the probable mechanisms concerning Co 3 O 4 -composite spinel activated PMS were proposed. . Parameters involved in different reaction temperatures and Co 3 O 4 -composite spinels/ PMS systems: (e) Arrhenius curves; (f) DPMS. Experimental condition: [ENR] ¼ 10 mg L À1 , [catalyst] ¼ 0.1 g L À1 , [PMS] ¼ 1 mM, pH 0 ¼ 6.This journal is Fig. 9 (a) Reusability of different Co 3 O 4 -composite spinels as catalyst for the degradation of ENR; (b) cobalt leaching concentrations in different Co 3 O 4 -composite spinels/PMS systems. Experimental condition: [ENR] ¼ 10 mg L À1 , [catalyst] ¼ 0.1 g L À1 , [PMS] ¼ 1 mM, pH 0 ¼ 6, T ¼ 25 C, reaction time ¼ 25 min.

Activation of Peroxymonosulfate by Oxygen Vacancies-Enriched Cobalt-Doped Black TiO2 Nanotubes for the Removal of Organic Pollutants

“…10 A variety of methods have been employed to generate SO 4 • – via PMS activation. 11−19 Transition-metal ions with multiple valence state are most frequently used for activation of PMS without the need for external energy inputs (e.g., UV light and electricity). 20…”

Catalytic activation of peroxymonosulfate with manganese cobaltite nanoparticles for the degradation of organic dyes

“…2 The catalytic activation of PMS is mostly based on transition metals such as Fe, Mn, Ni, Co, Cu and Ag in the forms of homogeneous or heterogeneous catalysts. 8 Although Co, Cu and Ag are excellent PMS activators, their relatively high toxicity (especially Co) and low abundance have hindered their practical uses. Moreover, the utilization of these transitional metals ions as homogeneous activators has several drawbacks such as difficult recovery of activators and secondary pollution.…”

CoMn2O4 Catalyst Prepared Using the Sol-Gel Method for the Activation of Peroxymonosulfate and Degradation of UV Filter 2-Phenylbenzimidazole-5-sulfonic Acid (PBSA)

“…However, their catalytic effects are not satisfactory, and drawbacks also exist, such as low catalytic activity, low oxidant utilization rate, and incomplete degradation of the organic intermediates. In order to improve the catalytic performance, different transition metals, such as Cu, Mn, Cr, Co, etc., have been added to the Fe 3 O 4 [30,31]. Alternatively, humic acid, EDTA, polyhydroquinone, etc., have been coated on the surface of the Fe 3 O 4 [32,33,34,35,36,37,38].…”