The primary phase of the Earth’s lower mantle, (Al, Fe)-bearing bridgmanite, transitions to post-perovskite (PPv) at deep mantle conditions. Despite extensive experimental and ab initio investigations, there are still important aspects this transformation that need clarification. Here, we address transition in (Al3+, Fe3+)-, (Al3+)-, (Fe2+)-, (Fe3+)-bearing bridgmanite using calculations valida...

CaFeO3-? perovskite nanomaterial has been synthesized by sol-gel method. Rietveld analysis of the X-Ray diffraction (XRD) data sample revealed orthorhombic structure (space group pcmn). Field emission scanning electron microscope (FE-SEM) showed agglomerations various particles. Mössbauer measurement that value ? is 0.262 and Fe oxidation states are Fe3+ in octahedral Fe4+ tetrahedral coordinat...

The Raman spectral patterns of analyzed natural titanomagnetite samples revealed peaks at 670-680 cm-1, 544-603 407-495 cm-1 and 373-392 that correspond to the A1g, T2g (2), (3) Eg vibrational modes spinel Fd3m space group. Previous studies spectra have suggested behavior these reflect distribution Fe2+-O, Fe3+-O Ti4+-O bonds within crystal structure. peak intensities each are observed be relat...

Ibuprofen (IBU), a nonsteroidal anti-inflammatory drug, is one of the most widely used and frequently detected pharmaceuticals personal care products in water bodies. This study examined IBU degradation aquatic solutions via ferric ion activated peroxydisulfate (PDS) coupled with electro-oxidation (EC/Fe3+/PDS). The mechanisms involved three synergistic reactions EC/Fe3+/PDS system, including: ...

Herein, a facile iron-sulfur double-doping strategy is developed for the synthesis of highly active FeNx/S-NC catalyst by pyrolysis double-doped polypyrrole precursor, PPy-Fe3+-SCN-. The unique precursor firstly prepared coordinating SCN- with Fe3+ ions adsorbed in situ into matrixes (PPy-Fe3+) during an oxidative polymerization process. Subsequent PPy-Fe3+-SCN- produced containing sites Fe-Nx ...

Mineral processing, pyro- and hydrometallurgical processes of auriferous sulfide ores porphyry copper deposits (PCDs) generate arsenopyrite-rich wastes. These wastes are disposed into the tailings storage facilities (TSF) in which toxic arsenic (As) is leached out acid mine drainage (AMD) generated due to oxidation arsenopyrite (FeAsS). To suppress oxidation, this study investigated passivation...

2014 57Fe Mössbauer spectroscopy has been combined with bulk magnetic measurements to determine the valence state and coordination of iron as well as the magnetic properties of the ternary oxide glasses, Li2O-B2O3Fe2O3. In all investigated glasses (~ 8.4 at % Fe), the Fe3+ ions coexist in tetrahedral and octahedral coordinations ; the presence of Fe2+ ions ( 15 %), which is observed in some gla...

Ferritins are iron storage proteins that overcome the problems of toxicity and poor bioavailability of iron by catalyzing iron oxidation and mineralization through the activity of a diiron ferroxidase site. Unlike in other ferritins, the oxidized di-Fe3+ site of Escherichia coli bacterioferritin (EcBFR) is stable and therefore does not function as a conduit for the transfer of Fe3+ into the sto...

To compare the catalytic oxidation activities of reduced graphene oxide (rGO) and rGO samples doped with five different transition metals (TM-rGO), we determine their effects on the oxidation of L-cysteine (Cys) in aqueous solution by performing electrochemistry (EC) measurements and on the photocatalytic oxidation of Cys by using high-resolution photoemission spectroscopy (HRPES) under UV illu...