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Carbon-based single metal atom catalysts (SACs) are being extensively investigated to improve the kinetics of the Li-S redox reaction, which is greatly important for batteries with cell-level energy densities500 W h kg

The development of reliable and safe high-energy-density lithium-ion batteries is hindered by the structural instability of cathode materials during cycling, arising as a result of detrimental phase transformations occurring at high operating voltages alongside the loss of active materials induced by transition metal dissolution. Originating from the fundamental structure/function relation of battery materials, the authors purposefully perform crystallographic-site-specific structural engineering on electrode material structure, using the high-voltage LiNi0.5 Mn1.5 O4 (LNMO) cathode as a representative, which directly addresses the root source of structural instability of the Fd 3¯ m structure. By employing Sb as a dopant to modify the specific issue-involved 16c and 16d sites simultaneously, the authors successfully transform the detrimental two-phase reaction occurring at high-voltage into a preferential solid-solution reaction and significantly suppress the loss of Mn from the LNMO structure. The modified LNMO material delivers an impressive 99% of its theoretical specific capacity at 1 C, and maintains 87.6% and 72.4% of initial capacity after 1500 and 3000 cycles, respectively. The issue-tracing site-specific structural tailoring demonstrated for this material will facilitate the rapid development of high-energy-density materials for lithium-ion batteries.

The detection and monitoring of nitrogen dioxide (NO2) plays a vital role in the environmental, healthcare, farming, and industrial sectors. However, the development of NO2 gas sensors with simultaneously high sensitivity, reversibility, low detection limit, and excellent selectivity remains challenging. In this work, an ultrasensitive NO2 gas sensor with superb selectivity and reversibility is demonstrated based on α-phase molybdenum trioxide (α-MoO3). Nanoribbons of α-MoO3 are synthesized via vapor phase transport (VPT) and systematically characterized using a combination of advanced characterization probes. At an optimal operating temperature of 125 °C, the α-MoO3-based sensor shows a very high sensitivity toward NO2 with a detection limit as low as 24 ppb, while also exhibiting excellent selectivity and reversibility. Such impressive performance originates from the layered nature of the α-MoO3 nanoribbons as well as the hierarchical assembly of the nanoribbons as the sensing layer. The study demonstrates a facile sensing platform based on α-MoO3 for ultrasensitive and selective NO2 gas sensing.

An abscopal effect refers to distant tumor regression after localized irradiation. The mechanism is thought to be via local radiotherapy triggering the immune system which then attacks distant tumor sites. Only several cases of solid tumors with an abscopal effect have been reported in the past few decades, and whether an abscopal effect can cross the blood-brain barrier is still unknown. Herein, we present a female patient who was admitted due to unsteady gait and dyspnea. Chest X-ray (CXR) and chest CT showed a huge lung mass with left lung collapse and multiple liver masses. Brain MRI also showed multiple brain metastases. A bronchoscopic biopsy proved metastatic adenocarcinoma from colorectal cancer based on immunohistochemical staining. She therefore received 30 Gy (10 fractions) for the brain metastases; however, she refused to receive any systemic therapy for her lung mass and asked for hospice care. She was therefore transferred to a nursing home and was lost to follow-up. She returned 2 months later due to right pneumonia with fever and productive cough. Surprisingly, her left lung mass had markedly regressed even though she had not received any additional systemic anticancer therapy. This may be the first case of an abscopal effect after receiving whole brain irradiation for brain metastases.

The development of oxygen reduction reaction (ORR) electrocatalysts based on earth-abundant nonprecious materials is critically important for sustainable large-scale applications of fuel cells and metal-air batteries. Herein, a hetero-single-atom (h-SA) ORR electrocatalyst is presented, which has atomically dispersed Fe and Ni coanchored to a microsized nitrogen-doped graphitic carbon support with unique trimodal-porous structure configured by highly ordered macropores interconnected through mesopores. Extended X-ray absorption fine structure spectra confirm that Fe- and Ni-SAs are affixed to the carbon support via FeN4 and NiN4 coordination bonds. The resultant Fe/Ni h-SA electrocatalyst exhibits an outstanding ORR activity, outperforming SA electrocatalysts with only Fe- or Ni-SAs, and the benchmark Pt/C. The obtained experimental results indicate that the achieved outstanding ORR performance results from the synergetic enhancement induced by the coexisting FeN4 and NiN4 sites, and the superior mass-transfer capability promoted by the trimodal-porous-structured carbon support.

Elektrochemisch gewachsenes Cobalt auf Graphen weist außergewöhnliche Katalysatoreigenschaften für die Sauerstoffentwicklungsreaktion (OER) auf und bietet die Möglichkeit, die Morphologie und die chemischen Eigenschaften während der Abscheidung zu kontrollieren. Es gibt allerdings noch kein ausreichendes Verständnis der atomaren Struktur dieses Hybridmaterials. Um die elektronische Struktur von Co/Graphen aufzuklären, haben wir eine Durchflusszelle entwickelt, die durch eine Graphenmembran abgeschlossen wird und elektronische und chemische Informationen über die aktiven Oberflächen unter atmosphärischem Druck und in der Gegenwart von flüssigen Elektrolyten unter Verwendung von Röntgenphotoelektronenspektroskopie (XPS) liefert. Wir konnten zeigen, dass Cobalt an Graphen über Carbonyl-ähnliche Spezies bindet, d. h. Co(CO)x , und so die Reduktion von Co3+ zu Co2+ fördert, das als aktives Zentrum des Katalysators vermutet wird.