Construction Of Tungsten-containing Films With Improved Photoelectrocatalytic Activity

Photoelectrocatalytic（PEC）technology is widely used in the degradation of organic pollutants containing in the waste water.The properties of the anode materials is important to the efficiency of the PEC.In this thesis,we synthetized Bi₂O₃-WO₃ and WO₃-Cu₂O films by different methods.Field emission scanning electron microscope（FESEM）,X-ray（XRD）,X-ray photoelectron spectroscopy（XPS）,UV-visible diffuse reflectance spectroscopy（DRS）,Photoluminescence（PL）and various electrochemical method was used to analysis the morphology,structure and the optical,electrical properties.The PEC performance of the films were investigated.The main research work is as follows:（1）A p-n heterojunction film of Bi₂O₃-WO₃ was synthetized by one-pot hydrothermal method.FESEM images showed the flower-like structures of the film,the XPS spectrum showed the existence of O,C,Bi and W elements.The XRD pattern of the prepared film presented the characteristic diffraction peaks ofα-Bi₂O₃ and WO₃,there are no other impurities formed in the composites film.The DRS spectrum showed that the absorption edge of Bi₂O₃-WO₃ is red-shift compared to single materials,the PL intensity of Bi₂O₃-WO₃film is obviously weaker than that of either Bi₂O₃ or WO₃ film.The CLSV and EIS proved the excellent optical response of the film.The PEC performance of the film was evaluated by the decoloration of Rh B,the best decoloration rate was 73.4%in 3 h,when the Bi/W ratio in the synthesis process was 5:6,the decoloration percentage was reduced by 13%after the fifth cycle.The PEC degradation efficiency of the films is better than either the single film or the photocatalytic and electrocatalytic performance.Furthermore,the film was used to degradate the NOR,a possible PEC degradation mechanism for NOR was proposed according to nine intermediates identified by liquid chromatograph-mass spectrometric analysis.（2）WO₃-Cu₂O composite film in the FTO conducting glass was constructed by two steps depositing method.The SEM image showed that the Cu₂O cubes evenly dispersed on the surface of the WO₃ nano-rods.The LSV and EIS indicated the optical response of the WO₃-Cu₂O film is stable and better than the single films,the PL intensity of the composite film is weaker that the single ones.The PEC performance of the film was evaluated by the decoloration of Rh B,the best decoloration rate was 56.5%in 2 h,when the electrodepositing time in the synthesis process was 5 min,the decoloration percentage was reduced by 13%after the fifth cycle.The PEC degradation efficiency of the films was better than either the single film or the photocatalytic and electrocatalytic performance.