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

Abstract

We investigated the reaction of manganese oxide [MnO_x(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 8-10% and the content of Mn(II) increased 12-15% in the surface of reacted MnO_x(s) compared to the control, indicating that the oxidation of organic compounds causes the reduction of MnO_x(s). Fitting of C 1s XPS spectra suggests an increase in the number of aromatic and aliphatic bonds for MnO_x(s) reacted with organic compounds. The presence of 2.7% Cl in the MnO_x(s) surface after reaction with triclosan was detected by XPS survey scans, while no Cl was detected in MnO_x-phenol, MnO_x-aniline, and MnO_x-control. Raman spectra confirm the increased intensity of carbon features in MnO_x(s) samples that reacted with organic compounds compared to unreacted MnO_x(s). These spectroscopy results indicate that phenol, aniline, triclosan, and related byproducts are associated with the surface of MnO_x(s)-reacted samples. The results from this research contribute to a better understanding of interactions between MnO_x(s) and organic compounds that are relevant to natural and engineered environments.