Realizing the rational design of perovskite oxides with controllable compositions and nanostructures remains a tremendous challenge for the development of efficient electrocatalysts. Herein, a ligand-assisted synthetic strategy to fabricate perovskite oxides LaCo Fe O with yolk-shell nanostructures is developed. Benefiting from the unique structural and compositional merits, LaCo Fe O exhibits an overpotential of 310 mV at a current density of 10 mA cm and long-term stability of 100 h for the oxygen evolution reaction. In situ Raman spectroscopy demonstrates that Fe substitution facilitates the pre-oxidation of Co sites and induces the surface reconstruction into active Co oxyhydroxides at a relatively lower applied potential, guaranteeing excellent catalytic performances. Density functional theory calculations unravel that the appropriate introduction of Fe into perovskite LaCoO leads to the improved electroactivity and durability of the catalyst for the oxygen evolution reaction (OER). Fe-3d orbitals show a pinning effect on Co-3d orbitals to maintain the stable valence state of Co sites at the low overpotential of the OER. Furthermore, Zn-air batteries (ZABs) assembled with LaCo Fe O display a high open circuit potential of 1.47 V, superior energy density of 905 Wh kg , and excellent stability in a large temperature range. This work supplies novel insights into the future developments of perovskite-based electrocatalysts.
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http://dx.doi.org/10.1002/smll.202201131 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Earth and Planetary Sciences, Yale University, New Haven 06511.
The origin of complex life and the evolution of terrestrial ecosystems are fundamental aspects of the natural history on Earth. Here, we present evidence for a protracted stabilization of the Earth's ozone layer. The destruction of atmospheric ozone today is inherently linked to the cycling of marine and atmospheric iodine.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095.
The elemental and isotopic abundances of major species in the Martian atmosphere have been determined, but analyses often lack sufficient precision, and those of minor and trace species are frequently not well known. Many important questions about the evolution and current state of Mars require the kind of knowledge that can be gained from analysis of a returned sample of the Martian atmosphere. Key target species include the noble gases, nitrogen, and various species containing carbon, hydrogen, and oxygen, such as methane.
View Article and Find Full Text PDFAndes Pediatr
October 2024
Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile.
Viral infections are the main cause of acute respiratory failure in infants, which can progress to acute respiratory distress syndrome (ARDS), with high morbidity and mortality, so it is essential to imple ment strategies that prevent this progression. Recently, it has been proposed that increased work of breathing would not only be a warning symptom during the evolution of acute respiratory failure, but also a mechanism for the progression of injury, both lungs and diaphragm, coining the concept of patient self-inflicted lung injury. Since the first reports of ARDS, the usefulness of the use of con tinuous positive airway pressure (CPAP) has been raised, a non-invasive respiratory support therapy with wide access and low cost, capable of improving oxygenation and work of breathing.
View Article and Find Full Text PDFAndes Pediatr
August 2024
Servicio de Neonatologia, Complejo Asistencial Dr. Sótero del Río, Santiago, Chile.
Unlabelled: Observational studies have described an increase in the duration of oxygen therapy, bronchopulmonary dysplasia (BPD), and retinopathy of prematurity (ROP) in relation to the use of high-flow nasal cannula (HFNC, 2013-2016).
Objective: to analyze changes in the evolution of very preterm newborns with the use of HFNC.
Patients And Method: The incidence of neonatal pathologies between 2013 and 2021 was analyzed with a statistical process control.
Chem Commun (Camb)
January 2025
Institute for Carbon Neutralization Technology, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, China.
Single-atom catalysts (SACs) have become the forefront and hotspot in energy storage and conversion research, inheriting the advantages of both homogeneous and heterogeneous catalysts. In particular, carbon-supported SACs (CS-SACs) are excellent candidates for many energy storage and conversion applications, due to their maximum atomic efficiency, unique electronic and coordination structures, and beneficial synergistic effects between active catalytic sites and carbon substrates. In this review, we briefly review the atomic-level regulation strategies for optimizing CS-SACs for energy storage and conversion, including coordination structure control, nonmetallic elemental doping, axial coordination design, and polymetallic active site construction.
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