Cobalt implanted TiO2 nanocatalyst for heterogeneous activation of peroxymonosulfate

In the past decades, catalyst stability and metal ions leaching have always been one of the most important issues in the heterogeneous peroxymonosulfate (PMS) activation system. In this work, cobalt implanted TiO2 was proposed as an effective catalyst for improving the catalyst stability and inhibiting cobalt leaching. A simple hydrolysis method was employed for the preparation of nanocatalysts with Co(NO3)(2)center dot 6H(2)O and Ti(OC3H7)(4) as precursors. Characterization by X-ray diffractometry, X-ray photoelectron spectroscopy and temperature programmed reduction indicated that the doped cobalt uniformly distributed in the faces of TiO2 crystallite as Co2+ and interacted with TiO2 through a strong Co-O-Ti bond. Compared to the Co3O4 immobilized TiO2 catalysts, the cobalt ion implanted TiO2 nanocatalysts reduced half of the cobalt dosage but exhibited paralleled catalytic activity and, moreover, the cobalt leaching declined about 60%. The reduction of cobalt dosage, uniform distribution of Co2+ in the TiO2 crystal lattice and the strong interaction of Co2+ with TiO2 support were believed to improve the performance in heterogeneous activation of peroxymonosulfate (PMS) and decrease the cobalt leaching.