A facile in situ redox strategy has been developed to fabricate surfactant-free M-Fe_2O_3(M = Pt, Pd, Au) hybrid nanospheres. In this process, noble metal salts were directly reduced by the pre-prepared Fe_3O_4 components in an alkaline aqueous solution without using organic reductants and surfactants. During the redox reaction, Fe_3O_4 was oxidized into Fe_2O_3,and the reduzates of noble metal nanoparticles were deposited on the surface of the Fe_2O_3 nanospheres. Then the characterizations were discussed in detail to study the formation of M-Fe_2O_3 hybrids. At last, catalytic CO oxidation was selected as a model reaction to evaluate the catalytic performance of these samples.It demonstrates that Pt-Fe_2O_3 nanospheres can catalyze 100 % conversion of CO into CO_2 at 90°C, indicating superior activity relative to Pd-Fe_2O_3 and Au-Fe_2O_3.
ZnWO4,as an environment-friendly and economic material,has the potential for Li ion batteries(LIB)application.In this paper,a facile method has been developed to synthesize ZnWO4supported on the reduced graphene oxide(RGO)to improve its LIB performance.The cuboid-like ZnWO4nanocrystals are prepared by directly adding Na2WO4 powders into the graphene oxide/Zn aqueous solution followed by a hydrothermal treatment.The high-resolution TEM,XRD and XPS characterizations were employed to demonstrate structural information of the as-prepared ZnWO4/RGO hybrids carefully.Besides,we also discussed the LIB properties of the hybrids based on the detailed galvanostatic charge-discharge cycling tests.As a result,the specific capacity of the as-prepared ZnWO4/RGO hybrids reached more than 477.3 mA h g 1after 40 cycles at a current density of 100 mA g 1(only less than 159 mA g 1for bare ZnWO4).During the whole cyclic process,the coulombic efficiency steadily kept the values higher than 90%.
