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In this paper, mesoporous Cu 2 O–CeO 2 nanospheres were fabricated via a facile, low-temperature solution route in the presence of poly(2-vinylpyridine)- b -poly(ethylene Oxide) (P2VP- b -PEO) block copolymers. The prepared mesoporous Cu 2 O–CeO 2 nanospheres were characterized systematically by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption/desorption. The formation mechanism of mesoporous Cu 2 O–CeO 2 nanospheres was discussed. The results show that the molar ratios of Ce 3+ /Cu 2+ and the reaction time have an important influence on the nanostructure of Cu 2 O–CeO 2 composite spheres. The resultant Cu 2 O–CeO 2 nanospheres exhibit superior catalytic activities in the reduction of 4-nitrophenol to 4-aminophenol by NaBH 4 . The activity factor (K =  k /m) for the Cu 2 O–CeO 2 nanospheres prepared with the molar ratio of Ce 3+ /Cu 2+ of 5/1 is 3006.6 s −1  g −1 , which is much higher than reported values. This paper demonstrates a highly controllable approach to the production of mesoporous Cu 2 O–CeO 2 nanospheres, which have potential applications in the areas of catalysis, adsorption, sensors and so on. [ABSTRACT FROM AUTHOR]

Anatase TiO 2 nanosheets (NSs) with high surface area have been prepared via a one-step thermal decomposition of titanium tetraisopropoxide (TTIP) in oleylamine (OM), and their adsorption capacities and photocatalytic activities are investigated by using methylene blue (MB) and methyl orange (MO) as model pollutants. During the synthesis procedure, only one type of surfactant, oleylamine (OM), is used as capping agents and no other solvents are added. Structure and properties of the TiO 2 NSs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption analysis, UV–vis spectrum, X-ray photoelectron spectroscopy (XPS) and Photoluminescence (PL) methods. The results indicate that the TiO 2 NSs possess high surface area up to 378 m 2 g − 1 . The concentration of capping agents is found to be a key factor controlling the morphology and crystalline structure of the product. Adsorption and photodegradation experiments reveal that the prepared TiO 2 NSs possess high adsorption capacities of model pollutants MB and high photocatalytic activity, showing that TiO 2 NSs can be used as efficient pollutant adsorbents and photocatalytic degradation catalysts of MB in wastewater treatment. [ABSTRACT FROM AUTHOR]

A simple approach towards the fabrication of Au-CeO 2 Janus-like nanoparticles is presented. Composite micelles of polystyrene- block -poly (ethylene oxide) (PS- b -PEO)/Ce(NO 3 ) 3 /HAuCl 4 with HAuCl 4 and Ce(NO 3 ) 3 precursors incorporated in the PEO domains are prepared first. By manipulating the pH value of the composite micelles solution, a redox reaction between Au(III) with Ce(III) in the PEO domains occurs and Au-CeO 2 Janus-like nanoparticles composed of a porous CeO 2 and an Au nanoparticle are generated. X-ray diffraction (XRD), UV–vis spectrum (UV), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements are employed to characterize the Janus-like nanoparticles. The catalytic degradation of methyl orange dye (MO) under ultrasonic irradiation is chosen as the test reaction to examine the catalytic activity of the Au-CeO 2 Janus-like nanoparticles. It is found that Au-CeO 2 Janus-like nanoparticles show higher activity than that of CeO 2 nanoparticles or Au-CeO 2 composite nanoparticles. The increased catalytic activity of Au-CeO 2 Janus-like nanoparticles is attributed to the exposed Au core on one side of the Janus nanoparticles and the Au-CeO 2 heterointerfaces. [ABSTRACT FROM AUTHOR]