Use of XPS to Identify the Oxidation State of Mn in Solid Surfaces of Filtration Media Oxide Samples from Drinking Water Treatment Plants

Abstract

X-ray photoelectron spectroscopy (XPS) was used to identify Mn(II), Mn(III), and Mn(IV) in the surfaces of pure oxide standards and filtration media samples from drinking water treatment plants through the determination of the magnitude of the Mn 3s multiplet splitting and the position and shape of the Mn 3p photo-line. The Mn 3p region has been widely studied by applied physicists and surface scientists, but its application to identify the oxidation state of Mn in heterogeneous oxide samples has been limited. This study shows that the use of both the Mn 3s multiplet splitting and the position and shape of the Mn 3p photo-line provides a feasible means of determining the oxidation state of manganese in complex heterogeneous, environmentally important samples. Surface analysis of filtration media samples from several drinking water treatment plants was conducted. While Mn(IV) was predominant in most samples, a mixture of Mn(III) and Mn(IV) was also identified in some of the filtration media samples studied. The predominance of Mn(IV) in the media samples was felt to be related to the maintenance of free chlorine (HOCl) at substantial concentrations (2-5 mg*L(-1) as Cl2) across these filters. XPS could be a useful tool to further understand the specific mechanisms affecting soluble Mn removal using MnOx-coated filtration media.

Selective Growth of Co-electrodeposited Mn2O3-Au Spherical Composite Network Towards Enhanced Non-enzymatic Hydrogen Peroxide Sensing

“…The splitting in the Mn 3s spectra arises from the exchange interaction between the core 3s and unpaired 3d valance electrons causing photoelectron ejection [38]. The DE values of 5.4 eV and 5.44 eV for the Mn 3s splitting of the pristine and composite samples as shown in Fig 9(b) and 9(d) match well with that of Mn 2 O 3 [38,39]. This further supports our previous conclusion that both the pristine as well as the composite samples are formed as Mn 2 O 3 .…”

Activity of MnOx–CeO2 catalysts in combustion of low concentrated methane

“…Windows characteristic of O 1s , Mn 2p , and Ce 3d are presented. The detailed inspection of the Mn 2p doublet at 640-600 eV suggests the presence of manganese in the oxidation states of II, III, and IV at the surface of the investigated Mn70 catalyst [36,37]. Simultaneously, the abundance of manganese(II) decreased with increasing the nominal content of Mn in the catalysts, while the content of superficial Mn(III) increased.…”

High-temperature desulfurization of hot coal gas on Mo modified Mn/KIT-1 sorbents

“…According to report of Cerrato et al, the oxidation states of Mn correlated directly with the multiple splitting value between Mn 5 S and Mn 7 S [47]. As shown in Fig.…”