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

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