| Heterogeneous photocatalysis on oxide semiconductors is a promising technology for removing organic pollution in wastwater and harvesting solar energy. The preparation of an excellent photocatalyst is one of the crucial topics in the field of photocatalysis.Coupled semiconductors are distinctive photocatalytic materials through assembled two or more kinds semiconductors with the different energy band structure. The wide bandgap semiconductor could be sensitized by narrow bandgap semiconductor in the coupled semiconductors, expanding the region of the spectral response. And the photo-induced carriers(electrons or holes) may easily transfer from one semconductor into the another driven by the difference of the energy levels of two semiconductors, resulting in enhanced of the carriers separation efficiency and the quantum efficiency.In this thesis, using hydrogen bubbles as dynamic templates, three-dimensional (3D) porous Sn-Cu alloy films have been electrodeposited on the substrates of 304 stainless steel foils. And the porous SnO2-Cu2O coupled films were prepared by heating the Sn-Cu alloy films in air. The morphologies,constitutes and structures of the Sn-Cu and SnO2-Cu2O porous films were investigated with canning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDS) and X-ray diffraction(XRD).The photocatalytic activities of the SnO2-Cu2O porous films were tested using Rhodamine B(RhB) as a simulated pollution, under a 125 W mercury lamp.The effects of the preparation parameters on the morphologies, constitutes, structures and photocatalytic performance of the films were investigated in detail. The main works are as follow:1.The influences of the electrodeposition parameters, such as current densities, compositions of electrolytes, temperature of the electrolytes, on the mophologies, constitutes and structures of the Sn-Cu alloys films were systematically studied. The results show that the porous Sn-Cu alloy could be obtained form a solution containing SnSO4 0.05 mol/L,CuSO4 0.0025～0.5 mol/L,H2SO4 1.5 mol/L,formaldehyde 7.0 mL/L and OP 0.001%,at 20℃and current densities of 2.5～6.0 A/cm2.The mophologies and contitutes of the alloys are depended on the composition of the electrolytes and current densities applied. There were more Cu6Sn5 phases in the films with the Sn/Cu ratio about 3:1.The alloys films posses the major pores of 10～50μm. The pore walls were made up of particles of about 500 nn.2.The influences of temperature and time of the heated oxidation on the SnO2-Cu2O coupled films were studied. The results showed that the coupled SnO2-Cu2O porous films could obtained after heated the alloy at 200℃for 2 h follow by 200～400℃for 1-4 h in air. The morphologies and Sn/Cu ratios of the SnO2-Cu2O films are similar to that of Sn-Cu alloys. CuO is also detected in the films if the temperature heated is above 400℃for 2 h or time heated is longer than 2 h at 400℃.3.Photocatalytic activity of the SnO2-Cu2O were tested by photodegradation of RhB.The results show that the activities of the fims are depended on the morphologies and constitutes of the films. The activities of the porous films are better than that of the plane films. The films with most activities for photodegradation RhB were obtained from heated the porous alloys with Sn/Cu ratio of 3:1 at 200℃for 2 h follow by 400℃for 2 h in air, the alloys were electrodeposited from a solution containing SnSO4 0.05 mol/L,CuSO40.01 mol/L,H2SO4 1.5 mol/L,formaldehyde 7.0 mL/L and OP 0.001%, at 20℃and current densities of 6.0 A/cm2.The photodegration performance and stability of the porous films are superior to that of the SnO2,Cu2O and others composite films with different Sn/Cu ratios.The reaction of the RhB photodegradation on the SnO2-Cu2O films is following the apparent first-order reacting kinetics. The excellent photocatalytic activity of the coupled SnO2-Cu2O films may be due to the porous morphology and suited Sn/Cu ratio.
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