The stability of hydroxylated terminations of the 0001 surface of α-FeO (hematite) is investigated computationally using PBE + calculations with dispersion corrections. Hydroxylated surfaces with low OH concentrations are found to be most stable in a range of the chemical potential of water of -0.95 eV > μ > -2.22 eV. These surfaces can be described as isolated Fe(OH) groups adsorbed on the dry hematite surface and are predicted to be the exposed termination of the 0001 surface in a wide range of relevant experimental conditions. Most investigated reduced surfaces, containing Fe in oxidation state +2, are only stable in a range of the chemical potential of oxygen μ < -2.44 eV, where bulk hematite is less than magnetite. The only reduced surface stable at a higher μ is derived from the most stable nonreduced hydroxylated surfaces by removing a single OH group per unit cell.
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http://dx.doi.org/10.1021/acsomega.4c02113 | DOI Listing |
J Fluoresc
January 2025
Department of Stem Cell and Regenerative Medicine and Medical Biotechnology, Centre for Interdisciplinary Research, D. Y. Patil Education Society, Kolhapur, Maharashtra, India.
A straightforward one-step hydrothermal method is introduced for synthesizing highly efficient red fluorescence carbon dots (R-CQDs), utilizing Heena leaf (Lawsonia inermis) powder as the carbon precursor. The resulting R-CQDs exhibit excitation at 540 nm and emission at 675 nm, a high absolute photoluminescence (PL) with quantum yield of 40% in ethanol. Various physicochemical characterization was employed to confirm successful formation of R-CQDs including UV-Vis Spectroscopy, Fourier Transform Infrared (FT-IR) Spectroscopy, X-ray diffraction Spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key (Guangdong-Hong Kong Joint) Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, College of Chemical and Chemical Engineering, Shantou University, Shantou, 515041, P. R. China.
RuO-based materials are considered an important kind of electrocatalysts on oxygen evolution reaction and water electrolysis, but the reported discrepancies of activities exist among RuO electrocatalysts prepared via different processes. Herein, a highly efficient RuO catalysts via a facile hydrolysis-annealing approach is reported for water electrolysis. The RuO catalyst dealt with at 200 °C (RuO-200) performs the highest activities on both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acid with overpotentials of 200 mV for OER and 66 mV for HER to reach a current density of 100 mA cm as well as stable operation for100 h.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Institute of Forest Science, Kangwon National University, Chuncheon 24341, Republic of Korea; Department of Forest Biomaterials Engineering, College of Forest and Environmental Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea. Electronic address:
Carbon dot-based nanozymes have gained significant attention, but their application in dye degradation remains limited due to low activity and challenges in recovery and reuse. To overcome these limitations, high peroxidase-active Co-doped carbon dots (CoCDs) with surface amines were synthesized via hydrothermal method and immobilized onto TEMPO-oxidized cellulose nanofibrils (TOCNF) aerogels using EDC/NHS coupling. For the first time, this study investigates the dye degradation efficiency of CDs nanozyme.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, Delhi, 110016, India.
Crystalline γ-FeO(OH) dominantly possessing ─OH terminals (𝛾-FeO(OH)), polycrystalline γ-FeO(OH) containing multiple ─O, ─OH, and Fe terminals (𝛾-FeO(OH)), and α-FeO majorly containing ─O surface terminals are used as electrocatalysts to study the effect of surface terminals on electrocatalytic nitrate reduction reaction (eNORR) selectivity and stabilization of reaction intermediates. Brunauer-Emmett-Teller analysis and electrochemically determined surface area suggest a high active surface area of 117.79 m g (ECSA: 0.
View Article and Find Full Text PDFInorg Chem
January 2025
State Key Laboratory of Molecular & Process Engineering, SINOPEC Research Institute of Petroleum Processing, Beijing 100083, China.
The ZSM-5 zeolite is the key active component in high-severity fluid catalytic cracking (FCC) catalysts and is routinely activated by phosphorus compounds in industrial production. To date, however, the detailed structure and function of the introduced phosphorus still remain ambiguous, which hampers the rational design of highly efficient catalysts. In this work, using advanced solid-state NMR techniques, we have quantitatively identified a total of seven types of P-containing complexes in P-modified ZSM-5 zeolite and clearly revealed their structure, location, and catalytic role.
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