Degradation of orange II by Fe@Fe2O3 core shell nanomaterials assisted by NaHSO3

Fe@Fe2O3 core shell nanomaterials with different Fe2O3 shell thickness were synthesized and the Fe@Fe2O3/NaHSO3 Fenton-like system was used for the decomposition of Orange II. The consequences are compared with traditional Fenton Fe@Fe2O3/H2O2 system. The Fe@Fe2O3/NaHSO3 system showed extremely good applicability under both strongly acidic and alkaline conditions. The new Fe@Fe2O3-(2)/NaHSO3 system led to more than 99% degradation in 30 s when the pH was 3, which indicated that the Fe@Fe2O3 material was not corroded during the process even under strongly acidic condition. The above Fe@Fe2O3-(2) material was prepared from nano-zero-valent iron aged in solution for 2 h to synthesize the Fe2O3 shell. The reaction mechanism of Fe@Fe2O3/NaHSO3 Fenton-like system was also concluded. The oxidation efficiency was highly improved due to rapid electron transfer between Fe core and Fe2O3 shell, which promoted the direct recycling of equivalent to Fe3+ and equivalent to Fe2+ and thus accelerated the generation of center dot SO4- and center dot OH radicals. (C) 2019 Elsevier Ltd. All rights reserved.