Sulfamethoxazole degradation by alpha-MnO 2 /periodate oxidative system: Role of MnO 2 crystalline and reactive oxygen species

Pollutant degradation via periodate ( IO_4^- ) and transitional metal oxides provides an economical, energy-efficient way for chemical oxidation process in environmental remediation. However, catalytic activation of periodate by manganese dioxide and the associated mechanism were barely investigated. In this study, four MnO 2 polymorphs (α-, β-, γ- and δ-MnO 2 ) were synthesized and tested to activate IO_4^- for the degradation of sulfamethoxazole (SMX). The reactivity of different MnO 2 structures followed the order of α-MnO 2 > β-MnO 2 > γ-MnO 2 > δ-MnO 2 , suggesting that the particular crystalline structure in α-MnO 2 would exhibit higher activities via IO_4^- activation. Herein, in α-MnO 2 / IO_4^- system, 91.1