Thermal Analysis of Photoelectron Emission (PE) and X-ray Photoelectron Spectroscopy (XPS) Data for Iron Surfaces Scratched in Air, Water, and Liquid Organics

Abstract

Little is known about the temperature dependence of electron transfer occurring at real metal surfaces. For iron surfaces scratched in seven environments, we report Arrhenius activation energies obtained from the data of photoelectron emission (PE) and X-ray photoelectron spectroscopy (XPS). The environments were air, benzene, cyclohexane, water, methanol, ethanol, and acetone. PE was measured using a modified Geiger counter during repeated temperature scans in the 25–339 °C range under 210-nm-wavelength light irradiation and during light wavelength scans in the range 300 to 200 nm at 25, 200, and 339 °C. The standard XPS measurement of Fe 2p, Fe 3p, O 1s, and C 1s spectra was conducted after wavelength scan. The total number of electrons counted in the XPS measurement of the core spectra, which was called XPS intensity, strongly depended on the environments. The PE quantum yields during the temperature scan increased with temperature, and its activation energies (ΔEaUp1) strongly depended on the environment, being in the range of 0.212 to 0.035 eV. The electron photoemission probability (αA) obtained from the PE during the wavelength scan increased with temperature, and its activation energies (ΔEαA) were almost independent of the environments, being in the range of 0.113–0.074 eV. The environment dependence of the PE behavior obtained from temperature and wavelength scans was closely related to that of the XPS characteristics, in particular, the XPS intensities of O 1s and the O2− component of the O 1s spectrum, the acid–base interaction between the environment molecule and Fe–OH, and the growth of non-stoichiometric FexO. Furthermore, the origin of the αA was attributed to the escape depth of hot electrons across the overlayer.

A Comparative Study of Structural, Optical and Electrical Properties of Fe-ZnO Nanoparticles Synthesized by Precipitation and Microwave Method for Photovoltaic Applications

“…A satellite peak at 717.68 Ev is observed, which is an indication of the Fe3+ states [45,46]. Additionally, the binding energy at 710.83 eV for 2p3/2 represents Fe2O3 chemical state [47]. Hence, it confirms the presence of Fe2O3 phase in nanoparticles synthesized by precipitation method [48].…”

RuFe Alloy Nanoparticle-Supported Mesoporous Carbon: Efficient Bifunctional Catalyst for Li-O2 and Zn–Air Batteries

“…Considering this range of peaks, which slightly expanded, the active sites of iron oxide got exposed during accelerated degradation. On the other hand, the case of the fitted C 1s spectra showed the bonding of C–C & CC (284.8 eV) and CO & O–CO (289∼289.5 eV) bonding species. , After the 120 h chronopotentiometry test, the proportion of oxidized carbon was increased by 7%, as we can infer from the C 1s XPS spectrum (Figure b). The postanalyses confirm the existence of oxidized carbon compared with the fresh electrode.…”

“…The following binding energies were referred and presented for iron oxides: 709.5 eV (FeO), 708. 51,52 After the 120 h chronopotentiometry test, the proportion of oxidized carbon was increased by 7%, as we can infer from the C 1s XPS spectrum (Figure 5b). The postanalyses confirm the existence of oxidized carbon compared with the fresh electrode.…”

Development of Microcontroller-Based System for Background Radiation Monitoring

“…It consists of the data processing module, components of the collection of environmental data and control, and components for the processed data displaying. The data collection is implemented using a radiation detector, a gas-discharge Geiger–Mueller SBM-20 meter [ 14 , 21 , 22 ].…”

“…The developed hardware of the microcontroller-based radiation monitoring system has a low cost and the modular structure [ 15 , 22 , 23 , 24 , 25 ] that makes it possible to rapidly improve the system.…”