Manganese Oxide Anodized from Manganese Films Electrodeposited at Different Cathodic Currents and its Capacitive Performance

2014 ◽  
Vol 926-930 ◽  
pp. 932-937 ◽  
Author(s):  
Wen Po Li ◽  
Xiu Li Zuo ◽  
Tang Man Lv ◽  
Sheng Tao Zhang
Keyword(s):  
Manganese Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Films ◽  
Oxide Coating ◽  
Oxide Surface ◽  
Nanostructured Films ◽  
Mn Oxide ◽  
Sulfate Solutions ◽  
Sem Study ◽  
Electro Oxidation

Nanostructured manganese oxide films were obtained by electro-oxidation of manganese films electrodeposited at two typical cathodic currents of 65 mA cm-2 (EDM-65 oxide) and 150 mA cm-2 (EDM-150 oxide) from sulfate solutions with additives. Obtained Mn oxide films were studied by scanning electron microscope, X-ray photoelectron spectroscopy, cyclic voltammetry and AC impedance. SEM study revealed that the Mn oxide films were mesoporous nanostructures on the EDM-150 oxide surface, while the EDM-65 oxide coating is homogeneous and compact. XPS results indicate that EDM-150 oxide had a higher content of anhydrous Mn oxide and structure water, which means that it had more anhydrous characteristics as compared to EDM-65 oxide. It was shown that porous nanostructured films showed good capacitive behavior for applications in electrochemical supercapacitors. The porous nanostructured films prepared at 150 mA cm-2 showed higher specific capacitance (SC) compared to the SC of the EDM-65 oxide films. The highest SC of 148 F g-1 in a voltage window of 0.8 V was obtained in 0.1 M Na2SO4 solutions at a scan rate of 25 mV s-1.

Oxygen Gettering Effect During the Reactive Evaporation of Manganese Oxide Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1653-1657 ◽  
Author(s):  
Masaaki Isai ◽  
Katsuma Yamaguchi ◽  
Haruhiko Iyoda ◽  
Hiroshi Fujiyasu ◽  
Yasumitsu Ito
Keyword(s):  
Manganese Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Films ◽  
Rapid Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Secondary Batteries ◽  
Reactive Evaporation ◽  
Mn Oxide

Manganese oxide films for lithium secondary batteries were prepared using a reactive evaporation method. Mn was evaporated from a molybdenum boat by resistive heating and deposited on a glass slide under oxygen atmosphere. These films were examined with x-ray photoelectron spectroscopy (XPS) and x-ray diffraction. The Mn oxide films with a wide valency of Mn were prepared in this study. A rapid change of the back pressure was found as the deposition of Mn was started. This implies that Mn atoms start to react with O2. This means that in situ detection of reactive evaporation process can be utilized.

Effects of heat-treatment on the spectroscopic and electrochemical properties of a mixed manganese/vanadium oxide film prepared by electrodeposition

2004 ◽  
Vol 19 (5) ◽  
pp. 1509-1515 ◽  
Author(s):  
Masaharu Nakayama ◽  
Akihiro Tanaka ◽  
Sayaka Konishi ◽  
Kotaro Ogura
Keyword(s):  
Oxide Film ◽  
Photoelectron Spectroscopy ◽  
Oxide Surface ◽  
Charge Balance ◽  
Electrically Conductive ◽  
Discharge Performance ◽  
Mn Oxide ◽  
Heat Treated ◽  
Steady State Current ◽  
Spin Resonance

Thin films of mixed manganese (mainly 4+) and vanadium (5+) oxides deposited electrochemically on a platinum substrate have been heat-treated under vacuum at various temperatures between 25 and 400 °C. Electron spin resonance and x-ray photoelectron spectroscopy revealed that the reductive formation of Mn2+ occurs at 300 °C only in the presence of vanadium within the film. This phenomenon can be regarded as a result of electron transfer from V4+ ions generated thermally to neighboring Mn sites. Voltammetric response of the heat-treated Mn/V oxide film in borate solution was enhanced with increasing the number of potential cycles, and the steady-state current was much larger than that of pure manganese oxide. Vanadate ions were diffused from the film to maintain the charge balance during the repetition cycles. The resultant porous structure can allow easier mass transport of protons to electrically conductive Mn oxide surface, offering the improved charge–discharge performance of the electrode.

scholarly journals Simultaneous Kinetics of Selenite Oxidation and Sorption on δ-MnO2 in Stirred-Flow Reactors

2021 ◽  
Vol 18 (6) ◽  
pp. 2902
Author(s):  
Zheyong Li ◽  
Yajun Yuan ◽  
Lin Ma ◽  
Yihui Zhang ◽  
Hongwei Jiang ◽  
...  
Keyword(s):  
Rate Constant ◽  
Photoelectron Spectroscopy ◽  
Oxide Surfaces ◽  
Kinetic Rate Constant ◽  
Flow Reactors ◽  
Mn Oxide ◽  
Remediation Strategies ◽  
Process Of Se ◽  
Kinetics Of

Selenium (Se) is an essential and crucial micronutrient for humans and animals, but excessive Se brings negativity and toxicity. The adsorption and oxidation of Se(IV) on Mn-oxide surfaces are important processes for understanding the geochemical fate of Se and developing engineered remediation strategies. In this study, the characterization of simultaneous adsorption, oxidation, and desorption of Se(IV) on δ-MnO2 mineral was carried out using stirred-flow reactors. About 9.5% to 25.3% of Se(IV) was oxidized to Se(VI) in the stirred-flow system in a continuous and slow process, with the kinetic rate constant k of 0.032 h−1, which was significantly higher than the apparent rate constant of 0.0014 h−1 obtained by the quasi-level kinetic fit of the batch method. The oxidation reaction was driven by proton concentration, and its rate also depended on the Se(IV) influent concentration, flow rate, and δ-MnO2 dosage. During the reaction of Se(IV) and δ-MnO2, Mn(II) was produced and adsorbed strongly on Mn oxide surfaces, which was evidenced by the total reflectance Fourier transform infrared (ATR-FTIR) results. The X-ray photoelectron spectroscopy (XPS) data indicated that the reaction of Se(VI) on δ-MnO2 produced Mn(III) as the main product. These results contribute to a deeper understanding of the interface chemical process of Se(IV) with δ-MnO2 in the environment.

scholarly journals On the Origin of the OER Activity of Ultrathin Manganese Oxide Films

2021 ◽  
Vol 13 (2) ◽  
pp. 2428-2436
Author(s):  
Paul Plate ◽  
Christian Höhn ◽  
Ulrike Bloeck ◽  
Peter Bogdanoff ◽  
Sebastian Fiechter ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Oxide Films

scholarly journals Mixed H2O/H2 Plasma-Induced Redox Reactions of Thin Uranium Oxide Films under UHV Conditions

2021 ◽  
Author(s):  
Ghada El Jamal ◽  
Thomas Gouder ◽  
Rachel Eloirdi ◽  
Evgenia Tereshina-Chitrova ◽  
Lukáš Horák ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Redox Reactions ◽  
Uranium Oxide ◽  
Oxide Films ◽  
X Ray ◽  
Gas Plasma

X-Ray Photoelectron Spectroscopy (XPS) has been used to study the effect of mixed H2O/H2 gas plasma on the surface of UO2, U2O5 and UO3 thin films at 400 °C. The...

Interface properties and electronic structure of ultrathin manganese oxide films on Ag(001)

2007 ◽  
Vol 601 (18) ◽  
pp. 4484-4487 ◽  
Author(s):  
M. Nagel ◽  
I. Biswas ◽  
H. Peisert ◽  
T. Chassé
Keyword(s):  
Electronic Structure ◽  
Manganese Oxide ◽  
Oxide Films ◽  
Interface Properties

Incorporation and Role of Nitrogen During Oxynitridation of Silicon Studied by Photoelectron Spectroscopy

1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Gaseous Mixtures ◽  
X Ray ◽  
Initial Stage ◽  
Thermal Stability Of

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.

scholarly journals Fabrication of Manganese Oxide/PTFE Hollow Fiber Membrane and Its Catalytic Degradation of Phenol

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3651
Author(s):  
Yan Wang ◽  
Diefei Hu ◽  
Zhaoxia Zhang ◽  
Juming Yao ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Hollow Fiber ◽  
Photoelectron Spectroscopy ◽  
Hollow Fiber Membrane ◽  
Weak Acid ◽  
Environmental Pollutant ◽  
Catalytic Degradation ◽  
Hollow Fiber Membranes ◽  
Fiber Membrane ◽  
Fiber Membranes

P-aminophenol is a hazardous environmental pollutant that can remain in water in the natural environment for long periods due to its resistance to microbiological degradation. In order to decompose p-aminophenol in water, manganese oxide/polytetrafluoroethylene (PTFE) hollow fiber membranes were prepared. MnO2 and Mn3O4 were synthesized and stored in PTFE hollow fiber membranes by injecting MnSO4·H2O, KMnO4, NaOH, and H2O2 solutions into the pores of the PTFE hollow fiber membrane. The resultant MnO2/PTFE and Mn3O4/PTFE hollow fiber membranes were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermal analysis (TG). The phenol catalytic degradation performance of the hollow fiber membranes was evaluated under various conditions, including flux, oxidant content, and pH. The results showed that a weak acid environment and a decrease in flux were beneficial to the catalytic degradation performance of manganese oxide/PTFE hollow fiber membranes. The catalytic degradation efficiencies of the MnO2/PTFE and Mn3O4/PTFE hollow fiber membranes were 70% and 37% when a certain concentration of potassium monopersulfate (PMS) was added, and the catalytic degradation efficiencies of MnO2/PTFE and Mn3O4/PTFE hollow fiber membranes were 50% and 35% when a certain concentration of H2O2 was added. Therefore, the manganese oxide/PTFE hollow fiber membranes represent a good solution for the decomposition of p-aminophenol.

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