We used thermogravimetric hydrogen reduction and iodometric titration to determine the bulk valence state of cobalt in Co-perovskites containing surface carbonate hydroxide or hydroxyl groups. It could be shown that thermogravimetric hydrogen reduction experiments are very sensitive to volatile surface groups, but due to their volatility, they can be specified and the bulk valence state of cobalt can still be deduced from these experiments. The iodometric titration is less sensitive to small volatile surface impurities, but precaution has to be taken that oxygen or iodine does not escape from the solution during dissolution of the sample. Best results were obtained if the sample was titrated during dissolution in a closed argon floated titration apparatus. We tested the two methods using LaCoO3 perovskite as a sample with a known valence state. Both methods delivered satisfactory results, and the valence state could be determined with an accuracy of better than 1%.
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http://dx.doi.org/10.1021/ac060903w | DOI Listing |
NbO(OH) has emerged as a highly attractive photocatalyst based on its chemical stability, energetic band positions, and large active lattice sites. Compared to other various photocatalytic semiconductors, it can be synthesized easily. This study presents a systematic analysis of pristine and doped NbO(OH) based on recent developments in related research.
View Article and Find Full Text PDFBackground: Positive alcohol expectancies are linked to increased alcohol use among college students. Difficulties regulating emotion have been shown to moderate this relationship, though little research accounts for differences based on the valence of the emotion being regulated.
Objective: To examine the independent moderating roles of positive and negative emotion dysregulation on the association between positive alcohol expectancies and alcohol use.
Psychophysiology
January 2025
Department of Psychology, University of Georgia, Athens, Georgia, USA.
Emotional experiences involve dynamic multisensory perception, yet most EEG research uses unimodal stimuli such as naturalistic scene photographs. Recent research suggests that realistic emotional videos reliably reduce the amplitude of a steady-state visual evoked potential (ssVEP) elicited by a flickering border. Here, we examine the extent to which this video-ssVEP measure compares with the well-established Late Positive Potential (LPP) that is reliably larger for emotional relative to neutral scenes.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.
Electrochemical oxidation of small molecules shows great promise to substitute oxygen evolution reaction (OER) or hydrogen oxidation reaction (HOR) to enhance reaction kinetics and reduce energy consumption, as well as produce high-valued chemicals or serve as fuels. For these oxidation reactions, high-valence metal sites generated at oxidative potentials are typically considered as active sites to trigger the oxidation process of small molecules. Isolated atom site catalysts (IASCs) have been developed as an ideal system to precisely regulate the oxidation state and coordination environment of single-metal centers, and thus optimize their catalytic property.
View Article and Find Full Text PDFJMIR Form Res
January 2025
Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, United States.
Background: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a multifactorial, chronic syndrome involving urinary frequency, urgency, and bladder discomfort. These IC/BPS symptoms can significantly impact individuals' quality of life, affecting their mental, physical, sexual, and financial well-being. Individuals sometimes rely on peer-to-peer support to understand the disease and find methods of alleviating symptoms.
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