Study On Preparation And Visible-Light Photocatalytic Performance Of PANI Loaded Cu₂O Magnetic Photocatalyst

With a unique photo-electric conversion property, semiconductor nanocatalyst has been widely applied in environmental control. Cuprous oxide(Cu2O) is a representative semiconductor catalyst, which exhibits high photocatalytic activity under visible light irradiation. However, it can be easily photo-corroded thus affect the lifetime. For photocatalytic reaction, besides the enhanced activity, high stability and a simply way to retrieve catalyst is also important. Obviously, only a single Cu2 O catalyst hardly meets all the requirements. Polyanline(PANI) possesses excellent conductivity and chemical stability. PANI-loaded semiconductor photocatalyst possesses a higher separation rate of photogenerated hole-electron pairs and catalytic effieciency. Therefore, Cu2O/Fe3O4 and PANI/Cu2O/Fe3O4 composite photocatalyst were synthesized in dissertation. Also the activities of the catalysts were tested. The research contents are as follows:Fe3O4 nanosphere and Cu Cl2·2H2O was used as raw materials while NH2OH·HCl was the reducing agent to prepare the Cu2O/Fe3O4 catalyst. Then aniline and p-toluenesulfonic acid(PTS) was employed as reactant and(NH4)2S2O8 was the initiator to synthesize PTS doping PANI. PANI was then dissolved in NMP and the as-prepared Cu2O/Fe3O4 powder was dispersed in the solution mentioned above. After 12 h of mechanical agitation, the PANI doped Cu2O/Fe3O4 composite catalyst was obtained. The doped and un-doped catalysts were characterized by X-ray diffractometer(XRD), transmission electron microscopy(TEM), field emission scanning electron microscopy(FE-SEM), fourier transform infrared spectrometer(FT-IR), vibrating sample magnetometer(VSM), respectively.Quinhydrone(HQ) was used as substrate to test the catalytic activity of Cu2O/Fe3O4. The influences of p H, amount of catalyst on degradation rate and life time of catalyst were investigated. P-nitrophenol(PNP) was employed to study the activity of PANI/Cu2O/Fe3O4 composite. The influences of photocatalysis and stability of catalyst were studied. Besides, the photodegradation efficiency of Cu2O/Fe3O4 and PANI/Cu2O/Fe3O4 was tested by HQ. The results revealed that HQ degradation efficiency in the presence of PANI doped catalyst was 95 %, which is 5% higher than that of un-doped one. The kinetic model and stability of catalyst were analyzed. After 5 recycles for degradation of PNP, the ratio still maintained at a relatively high level, suggesting doping can inhibit the photo-corrosion of Cu2 O.PNP and HQ were used as substrate to analyze the kinetic model of Cu2O/Fe3O4 and PANI/Cu2O/Fe3O4, respectively. The principle of photocatalysis was studied and the separation mechanism of photo-generated carriers was illuminated.