Caixin Guo

A controllable synthetic route to Cu, Cu2O, and CuO nanotubes and nanorods

Reducing Cu(OH)4(2-) with hydrazine hydrate and glucose in the presence of a structure-directing surfactant at room temperature gave Cu and Cu2O nanotubes/nanorods, respectively, whereas facile hydrothermal treatment of Cu(OH)4(2-) precursor resulted in CuO nanotubes/nanorods.

Preparation, characterization and photochemical properties of ordered macroporous hybrid silica materials based on monovacant Keggin-type polyoxometalates

High loading, three-dimensionally ordered macroporous (3DOM) hybrid silica materials based on monovacant Keggin-type polyoxometalates (POMs) [Xn+W11O39](12 − n)− (XW11; Xn+ = P5+, Si4+, Ge4+, B3+) were prepared via sol–gel as well as templating techniques. XW11 clusters were incorporated into the wall structures of macroporous silica, resulting in hybrid XW11–SiO2 composites. Formation of the hybrid materials was due to the chemical grafting of organosilanol groups from the silica network onto the surface oxygen atoms at vacant sites on the XW11 clusters. The products were characterized by UV diffuse reflectance spectra (UV/DRS), infrared (IR) spectra, 29Si and 31P MAS NMR, inductively coupled plasma atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption isotherms. The study indicates that the primary Keggin structures remain intact in the hybrid materials, and that the products demonstrate three-dimensionally ordered macropores with pore diameters in the range of 285 to 385 nm. The composites exhibited photocatalytic activity to degrade aqueous malic acid (MA) under irradiation in the near-UV region; leakage of XW11 from the hybrid materials was hardly observed during catalytic tests.