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Abstract: A series of Ce1−x Cu x O2 nanocomposite catalysts with various copper contents were synthesized by a simple hydrothermal method at low temperature without any surfactants, using mixed solutions of Cu(II) and Ce(III) nitrates as metal sources. These bimetal oxide nanocomposites were characterized by means of XRD, TEM, HRTEM, EDS, N2 adsorption, H2-TPR and XPS. The influence of Cu loading (5–25mol%) and calcination temperature on the surface area, particle size and catalytic behavior of the nanocomposites have been discussed. The catalytic activity of Ce1−x Cu x O2 nanocomposites was investigated using the test of CO oxidation reaction. The optimized performance was achieved for the Ce0.80Cu0.20O2 nanocomposite catalyst, which exhibited superior reaction rate of 11.2×10−4 mmolg−1 s−1 and high turnover frequency of 7.53×10−2 s−1 (1% CO balanced with air at a rate of 40mLmin−1, at 90°C). No obvious deactivation was observed after six times of catalytic reactions for Ce0.80Cu0.20O2 nanocomposite catalyst. [Copyright &y& Elsevier]

Abstract: Carbon nanotubes (CNTs) were controllably coated with the uninterrupted CuO and CeO2 composite nanoparticles by a facile pyridine-thermal method and the high catalytic performance for CO oxidation was also found. The obtained nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction as well as X-ray photoelectron spectroscopy. It is found that the CuO/CeO2 composite nanoparticles are distributed uniformly on the surface of CNTs and the shell of CeO2/CuO/CNT nanocomposites is made of nanoparticles with a diameter of 30–60nm. The possible formation mechanism is suggest as follows: the surface of CNTs is modified by the pyridine due to the π–π conjugate role so that the alkaline of pyridine attached on the CNT surface is more enhanced as compared to the one in the bulk solvent, and thus, these pyridines accept the proton from the water molecular preferentially, which result in the formation of the OH− ions around the surface of CNTs. Subsequently, the metal ions such as Ce3+ and Cu2+ in situ react with the OH− ions and the resultant nanoparticles deposit on the surface of CNTs, and finally the CeO2/CuO/CNT nanocomposites are obtained. The T 50 depicting the catalytic activity for CO oxidation over CeO2/CuO/CNT nanocomposites can reach ∼113°C, which is much lower than that of CeO2/CNT or CuO/CNT nanocomposites or CNTs. [Copyright &y& Elsevier]

Abstract: Solid-phase photocatalytic degradation of polyethylene (PE) plastic, one of the most common commercial plastic, over copper phthalocyanine (CuPc) modified TiO2 (TiO2/CuPc) photocatalyst was investigated in the ambient air under solar light irradiation. Higher PE weight loss rate, greater texture change; more amount of generated CO2, which is the main product of the photocatalytic degradation of the composite PEC plastic can be achieved in the system of PE–(TiO2/CuPc) in comparison with PE–TiO2 system. The CuPc promoted charge separation of TiO2 and enhanced the photocatalytic degradation of PE based on the analysis of surface photovoltage spectroscopy (SPS). During the photodegradation of PE plastic, the reactive oxygen species generated on TiO2 or TiO2/CuPc particle surfaces play important roles. The present study demonstrates that the combination of polymer plastic with TiO2/CuPc composite photocatalyst in the form of thin film is a practical and useful way to photodegrade plastic contaminants under solar light irradiation. [Copyright &y& Elsevier]