Preparation And Properties Of Cu₂O/（Ag, Cu） Composite Nanospheres

As a p-type semiconductor, due to its unique physical and chemical properties, nanostructured Cu2O exhibits excellent performances in environment protection, energy storage, conversion and so forth. In this paper, Cu2O nanospheres have been prepared by sample liquid phase method, using hydrazine hydrate as reductant, copper acetate as copper source and we modified the Cu2O nanospheres with Ag and Cu nanoparticles. Their photocatalytic and electrochemical performances have been investigated. The main points are summarized as follows:1. Cu2O/Ag composite nanospheres (CNSs) with tunable Ag coverage and optical properties have been prepared based on a one-pot room temperature method by adding AgNO2 solution to fresh Cu2O nanosphere-produced mother solution in various ratios. Ag+ions can be reduced by the primary Cu2O nanospheres in the acidic solution, and the obtained Ag nanoparticles can be deposited on the surfaces of the Cu2O nanospheres. The photocatalytic activity of Cu2O/Ag CNSs has been evaluated for photodegradation of methyl orange (MO) dye under visible-light irradiation, which demonstrates that Cu2O nanospheres with Ag loading exhibit signi fi cantly enhanced photocatalytic activity compared with pure Cu2O counterparts, and their photocatalytic properties depend on the coverage density of Ag nanoparticles. The enhanced photocatalytic activity can be attributed to the deposition of Ag acting as electron sinks to prevent the recombination of the photogenerated electrons and holes, and the plasmon resonances of the Ag nanoparticles generating more electron-hole pairs in the semiconductor.2. Cu2O/Cu composite nanospheres (CNSs) with tunable Cu coverage have been prepared based on a one-pot room temperature method by adding ascorbic acid to fresh CU2O nanosphere-produced mother solution in various ratios. As lithium-ion battery anode materials, the influence of Cu contentto the electrochemical performance has been investigated. The results show that discharge specific capacity of the Cu2O/Cu CNSs is higher than that of Cu2O, but the discharge specific capacity decrease with increasingthe content of Cu. The cycle performance and rate capability of the Cu2O/Cu CNSs are superior to Cu2O nanospheres. On the one hand, Cu on the surface of the CNSs improves the conductivity of Cu2O, which is conducive to the electronic conduction; On the other hand, Cu nanoparticles can be used as a catalyst to promote the decomposition of Li2O and SEI, reducing capacity loss.