Nano Fe_(2)O_(3)embedded in montmorillonite with citric acid enhanced photocatalytic activity of nanoparticles towards diethyl phthalate

Nano-Fe_(2)O_(3)embedded in montmorillonite particles(Fe-Mt)were prepared to degrade diethyl phthalate(DEP)with citric acid(CA)under xenon light irradiation.Compared to pristine montmorillonite(Na-Mt),the embedding process increased 14.5-fold of iron content and 1.8-fold of specific surface area.The synthesized Fe-Mt have more oxygen vacancies than Fe_(2)O_(3)nanoparticles(nFe_(2)O_(3)),which could induce more reactive oxygen species(ROSs)generation in the presence of CA under xenon lamp irradiation.Fe-Mt with CA enhanced photo-assisted degradation of DEP 2.5 times as compared to nFe_(2)O_(3)with CA.Quenching experiments,electron paramagnetic resonance(EPR)spectroscopy and identification of products confirmed that surface-bound·OH was the main radical to degrade DEP.Common anions(i.e.,NO_(3)-,CO_(3)^(2-),Cl^-)and humic acid could compete·OH with DEP and cause slower degradation of DEP.The removal efficiency of DEP was more than 56%with Fe-Mt after three recycles,and the dissolved Fe concentration from Fe-Mt was below 75μmol/L,indicating Fe-Mt had a good stability as a catalyst.Fe-Mt together with CA appeared to be a promising strategy to remove organic pollutants in surface water,or topsoil under solar irradiation.