Heterogeneous activation of peroxymonosulfate with cobalt incorporated fibrous silica nanospheres for the degradation of organic pollutants in water

Abstract

For activation of peroxymonosulfate (PMS) into reactive oxygen species (ROS), the catalysts with highly exposed active sites and improved mass transfer efficiency is desirable. Herein, cobalt incorporated fibrous silica nanospheres (Co-X/KCC-1) were fabricated by a one-step hydrothermal procedure and used for the first time for PMS activation to degrade phenol and other organic pollutants. In 9.0 minutes, Phenol degradation in the Co-30/KCC-1/PMS process, adsorption, sole PMS, and KCC-1/PMS processes reached almost 100%, 3.91%, 15% and 17% respectively. Moreover, 0.01 mg L−1 of Co was leached from Co-30/KCC-1 during reaction. Morphology, structure, texture, and catalytic activity of Co-30/KCC-1 were well-retained after recycling. The use of EPR and scavengers indicated that SO4−, OH, 1O2, and O2− were produced during catalysis with contribution in the order of 1O2 > O2− > SO4− >OH. In-situ ATR-FTIR, EIS, and XPS showed that the surface complex, and redox couple (Co(II)/Co(III) were responsible for the efficient ROS generation. The high catalytic activity was attributed to highly exposed active sites, radially oriented fibrous morphology, improved textural properties, and the generation of ROS. This research may provide an insight into the use of other metal/metal oxides (Fe, Mn, Cu) incorporated KCC-1 for PMS activation.