Electrospun nanoscale iron oxide-decorated carbon fiber as an efficient heterogeneous catalyst for activating percarbonate to degrade Azorubin S in water

Sodium percarbonate (2Na(2)CO(3)center dot 3H(2)O(2)) (PC) represents a promising alternative to H2O2 as PC is solid-phase, making it easier to handle; however iron (Fe) species are usually necessitated to activate PC for effectively producing hydroxyl radicals (HR) in degradation of toxicants. As homogeneous Fe species leads to severe issues of precipitation, heterogeneous iron oxide nanoparticles (NPs) seem promising but these NPs tend to aggregate in water. Thus, it is critical to develop supported iron oxide NPs. Since carbonaceous materials are one of the most useful supports, carbonaceous materials can be even fabricated into special morphologies to support iron oxide NPs. Herein, we propose to employ the electmspinning technique to develop carbon fiber (CF) as an advantageous carbon support because CF has a large aspect ratio (50:1) to allow iron oxide NPs well decorated on CF, forming a promising iron oxide NP-decorated CF (FeCF) for PC activation. FeCF is characterized using SEM, TEM, XRD, XPS, Raman spectroscopy and N-2 sorption isotherm. This FeCF can exhibit a noticeably higher catalytic reactivity than pristine Fe2O3 NPs for activating PC to generate HR, and then degrade a toxicant, Azorubin S (AZS). FeCF also exhibits a much lower activation energy (E-a) value of AZS degradation than other reported catalysts. Besides, FeCF could be also reusable to activate PC for degradation of AZS. Additionally, the degradation mechanism of AZS by FeCF-activated PC is also elucidated to provide insights into activation of PC and its environmental applications. These features prove that FeCF is an efficient heterogeneous catalyst to activate PC for degrading toxicants in aqueous solutions.

Automated summary

Sodium percarbonate (PC) is a promising alternative to H2O2 that requires iron (Fe) for activation. Developing supported iron oxide nanoparticles (NPs) on carbon fiber (CF) using electrospinning technique can effectively activate PC to degrade toxicants. FeCF shows higher catalytic reactivity and lower activation energy in degrading toxicants compared to other catalysts, making it a reusable and efficient heterogeneous catalyst in aqueous solutions.