Activation of persulfate by Co3O4 nanoparticles for orange G degradation

作者：Zhang, Jing^*; Chen, Mengyan; Zhu, Liang

来源：RSC Advances, 2016, 6(1): 758-768.

DOI：10.1039/c5ra22457h

• CATALYZED PEROXYMONOSULFATE OXIDATION
• FREE-RADICAL REACTIONS
• SULFATE RADICALS
• AQUEOUS-SOLUTIONS
• HETEROGENEOUS ACTIVATION
• TEXTILE WASTEWATERS
• HYDROXYL RADICALS
• GRAPHENE OXIDE
• RATE CONSTANTS
• CHLORIDE-IONS

Nano-Co3O4 was prepared by a precipitation method and successfully applied as a heterogeneous catalyst to activate persulfate (PS). The heterogeneous character of PS activation with nano-Co3O4 was more pronounced at neutral pH as indicated by the maximum degradation rate of orange G (OG) and the low concentration of dissolved cobalt ions. The increasing dosages of nano-Co3O4 and PS, and the higher temperature rapidly promoted the degradation kinetics of OG. Sulfate radicals (SO4 center dot-) and hydroxyl radicals (center dot OH) were proved to be the primary oxidative species, although the intensity of DMPO-OH signals were much stronger than that of DMPO-SO4 due to the fast transformation from DMPO-SO4 to DMPO-OH. The catalyst presented an acceptable stability through using it in five consecutive runs. The degradation pathways of OG in nano-Co3O4/PS process were proposed for the first time based on LC-MS analysis. The effects of Cl-, NO3-, HCO3-, Co2+, Fe2+ and Mn2+ ions, which usually co-exist as water matrix chemicals with azo-dyes, on OG removal by nano-Co3O4/ PS were examined intensively. The reactivity of potassium persulfate (PS), sodium persulfate (NaPS) and potassium peroxymonosulfate (PMS) in the presence of nano-Co3O4 followed the order of nano-Co3O4/ PMS > nano-Co3O4/ PS > nano-Co3O4/NaPS.

• 出版日期2016
• 单位河海大学