The mesoporous nanorod-like ceria with high BET surface area of 121 m2/g is prepared by a facile method, microwave-assisted hydrolysis of Ce(NO3)3·6H2O in presence of urea. As compared to bulk ceria, its absorption edge significantly shifts to the visible region with a band gap of as low as 2.75 eV due to the presence of Ce3+. A novel strategy of significantly improving its photocatalytic efficiency is developed by coupling oxygen ion conduction to photocatalysis in the mesoporous nanorod-like ceria, in which UV–visible photons and thermal energy from a Hg lamp were integrated. Under such photothermocatalytic oxidation conditions, the mesoporous nanorod-like ceria exhibits much higher photothermocatalytic activity for the gas-phase minerlization of organic contaminants than corresponding alone thermocatalytic and photocatalytic activity and good photothermocatalytic stability. The significantly enhanced mobility of oxygen ions with increasing temperature raised by thermal energy from the Hg lamp greatly improves the separation efficiency of photogenerated electrons and holes by UV–vis photons in the mesoporous nanorod-like ceria. Moreover, the hole-trapped lattice oxygen ion generated by UV–vis irradiation is more active than the lattice oxygen ion for benzene oxidation. These beneficial effects promote catalytic efficiency for gas-phase purification of organic contaminants such as benzene, hexane, and actone.

AgI/TiO 2 nanocomposite was prepared and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and diffusive reflectance UV-vis (DRUV-vis) absorption spectra at different temperatures. The AgI/TiO 2 nanocomposite exhibits thermochromic switching phenomena at the phase b-a transition temperature of AgI with the evolution of its color from light yellow at ambient temperature to dark khaki at 150 C. It was found for the first time that the formation of the AgI/TiO 2 nanocomposite not only results in a considerable reduction of thermochromic transition temperature of AgI as well as excellent thermochromic reversibility, but also leads to excellent photostability under illumination with an indoor fluorescent lamp. Based on the characterization results by photoluminescence, transient photocurrent decay and positron annihilation spectra, it is concluded that large surface defects, such as I À vacancy clusters (e.g. Ag + -I À V -Ag + -I À V -Ag + ) on the surface of AgI as deep electron traps, are responsible for the photodecomposition of pure AgI. The excellent photostability of the AgI/TiO 2 nanocomposite is due to the following reason: the surface I À vacancy clusters as deep electron traps in pure AgI are replaced by Ag + -O 2À -Ti 4+ bonds on the interface of AgI/TiO 2 , thus Ag n cluster formation through the surface migration of photogenerated Ag atoms is completely inhibited, resulting in the inhibition of photodecomposition of AgI.

Unique mesoporous microcuboid CeO 2 crystals were prepared by a facile method, involving the hydrothermal hydrolysis of a Ce(NO 3 ) 3 aqueous solution in the presence of urea at 180 C followed by calcination at 400 C, and characterized with XRD, SEM, TEM, BET, Raman, XPS, positron annihilation spectroscopy and TPR. It was found for the first time that the presence of densely populated mesopores in the microcuboid CeO 2 crystals results in highly reactive surface lattice oxygen due to the exposure of the mesopore wall surface with high interfacial curvature, thus leading to a significant enhancement in catalytic activity as compared to single crystal CeO 2 nanocubes without mesopores.

No abstract

Astilbin caused a significant improvement in lipid metabolism in HFD-fed mice. Astilbin could reduce weight gainand insulin resistance in obese individuals and modify intestinal microbiota disorders, lipid metabolism, and xanthine metabolism.