Spectroscopic Investigation of Interfacial Interaction of Manganese Oxide with Triclosan, Aniline, and Phenol

We investigated the reaction of manganese oxide [MnOx(s)] with phenol, aniline, and triclosan in batch experiments using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and aqueous chemistry measurements. Analyses of XPS high-resolution spectra suggest that the Mn(III) content increased 810% and the content of Mn(II) increased 1215% in the surface of reacted MnOx(s) compared to the control, indicating that the oxidation of organic compounds causes the reduction of MnOx(s). Fitting of C 1s XPS spectra suggests an increase in the number of aromatic and aliphatic bonds for MnOx(s) reacted with organic compounds. The presence of 2.7% Cl in the MnOx(s) surface after reaction with triclosan was detected by XPS survey scans, while no Cl was detected in MnOx-phenol, MnOx-aniline, and MnOx-control. Raman spectra confirm the increased intensity of carbon features in MnOx(s) samples that reacted with organic compounds compared to unreacted MnOx(s). These spectroscopy results indicate that phenol, aniline, triclosan, and related byproducts are associated with the surface of MnOx(s)-reacted samples. The results from this research contribute to a better understanding of interactions between MnOx(s) and organic compounds that are relevant to natural and engineered environments