Developing efficient oxygen evolution reaction (OER) electrocatalysts can greatly advance the commercialization of proton exchange membrane (PEM) water electrolysis. However, the unclear and disputed reaction mechanism and structure-activity relationship of OER pose significant obstacles. Herein, the active site and intermediate for OER on AuIr nanoalloys are simultaneously identified and correlated with the activity, through the integration of in situ shell-isolated nanoparticle-enhanced Raman spectroscopy and X-ray absorption spectroscopy.
View Article and Find Full Text PDFUnderstanding the fundamental insights of oxygen activation and reaction at metal-oxide interfaces is of significant importance yet remains a major challenge due to the difficulty in in situ characterization of active oxygen species. Herein, the activation and reaction of molecular oxygen during CO oxidation at platinum-ceria interfaces has been in situ explored using surface-enhanced Raman spectroscopy (SERS) via a borrowing strategy, and different active oxygen species and their evolution during CO oxidation at platinum-ceria interfaces have been directly observed. In situ Raman spectroscopic evidence with isotopic exchange experiments demonstrate that oxygen is efficiently dissociated to chemisorbed O on Pt and lattice Ce-O species simultaneously at interfacial Ce defect sites under CO oxidation, leading to a much higher activity at platinum-ceria interfaces compared to that at Pt alone.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2021
The Co-based electrocatalyst is among the most promising candidates for electrochemical oxidation of 5-hydroxymethylfurfural (HMF). However, the intrinsic active sites and detailed mechanism of this catalyst remains unclear. We combine experimental evidence and a theoretical study to show that electrogenerated Co and Co species act as chemical oxidants but with distinct roles in selective HMF oxidation.
View Article and Find Full Text PDFCaloric restriction (CR) is explored to limit the caloric intake without malnutrition. CR can affect the levels of various metabolites in organism, such as lipids, free fatty acids, ketones, bile acids and amino acids, etc, and is thought being able to extend the lifespan, postpone and reduce the incidence of age-related disorders (e.g.
View Article and Find Full Text PDFPlasmonic metal-semiconductor nanocomposites, especially those with core-shell nanostructures, have received extensive attention as they can efficiently expand light absorption and accelerate electron-hole separation thus improving the photocatalytic efficiency. However, controlled synthesis and structure manipulation of plasmonic metal-semiconductor nanocomposites still remain a significant challenge. Herein, a simple and universal method has been developed for the preparation of plasmonic Au@TiO core-shell nanoparticles.
View Article and Find Full Text PDFWorld J Gastrointest Pathophysiol
December 2011
The obesity epidemic imposes a significant health burden on human beings. Current understanding of the mechanisms underlying the development of obesity is incomplete and contemporary treatment is often ineffective. Gastrointestinal hormones are important regulators of food intake and energy metabolism.
View Article and Find Full Text PDFSheng Li Ke Xue Jin Zhan
April 2008
Beijing Da Xue Xue Bao Yi Xue Ban
October 2007
Objective: To construct a detection method of endogenous hydrogen sulfide (H2S) from erythrocytes.
Methods: Prepared rat erythrocyte (10(6) cell) was added in 4 mL 2-amino-2-methyl-1,3-propanediol(225 mmol/L, pH=9.55) and ultrasonically lysed for 3 times.