Magnetic CoFe2O4 nanoparticles supported on titanate nanotubes (CoFe2O4/TNTs) as a novel heterogeneous catalyst for peroxymonosulfate activation and degradation of organic pollutants.

Magnetic spinel ferrites, as heterogeneous catalysts to generate powerful radicals from peroxymonosulfate (PMS) for the degradation of organic pollutants, have received much attention in recent years due to the characteristic of environmental benefits. In this study, with titanate nanotubes (TNTs) as catalyst support, a novel CoFe2O4/TNTs hybrid was constructed by an impregnation-calcination method. Characterization results revealed that TNTs support could promise small size and good dispersion of CoFe2O4 nanoparticles. Compared to the pure CoFe2O4, the as-prepared CoFe2O4/TNTs not only exhibited better performance in catalytic decomposition of Rhodamine B, but also realized higher total organic carbon removal and less cobalt leaching, which could be attributed to the enhanced catalytic ability from smaller CoFe2O4 nanoparticles and the unique ion-exchange ability from TNTs support. Some influential factors, including reaction temperature, dosages of PMS and CoFe2O4/TNTs, and pH values were investigated and analyzed. Moreover, CoFe2O4/TNTs maintained its catalytic efficiency during the repeated batch experiments and also displayed functional advantages in the catalytic degradation of phenol. We believe the CoFe2O4/TNTs hybrid can be an efficient and green heterogeneous catalyst for the degradation of organic pollutants, and this study provides insights into the rational design and development of alternative catalysts for wastewater treatment.