Ferric-assisted Photoelectrocatalytic Degradation Of Rhodamine B

A Co,N,P/TiO2/SiO2/CoFe2O4 composite was synthesized via a sol-gel method,where SiO2/CoFe2O4 represent a core shell magnetic particles consisting of cobalt ferrite and silica.It was applied to the photoelectrocatalytic degradation of Rhodamine B(RhB),where using the xenon lamp as light source,using direct-current main as power sourse and using Na2SO4 as electrolyte.Five kinds of magnetic particle materials have been made by sol-gel method,which is SiO2/CoFe2O4,Ti02/SiO2/CoFe204,Co/Ti02/SiO2/CoFe204,N,P/Ti02/Si02/CoFe2O4 and Co,N,P/TiO2/SiO2/CoFe2O4.And all of them have been applied to the photoelectrocatalytic degradation of Rhodamine B,the result shows that the Co,N,P/TiO2/SiO2/CoFe2O4 have best performance wehter in adsorption of RhB or in photoelectrocatalytic degradation of Rhodamine B.The Co,N,P/TiO2/SiO2/CoFe2O4 was characterized by scanning electron microscope(SEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetric Analysis-differential scanning calorimetry(TG-DSC)and vibrating sample magnetometer(VSM).The SEM result shows that the Co,N,P/TiO2/SiO2/CoFe2O4 have more holes in surface,and own a bigger superficial area than TiO2/SiO2/CoFe2O4.The XRD result shows that the TiO2 in Co,N,P/TiO2/SiO2/CoFe2O4 is anatase crystal,and the CoFe2O4 in Co,N,P/TiO2/SiO2/CoFe2O4 Spinel crystal.The XPS result shows that Co?N?P have been successful doped into TiO2,and the proportion of Co,N,P,O,Ti,Si is 1.22%,1.28%,2.05%,59.90%,14.9%and 20.65%in the surface of the material.The TG-DSC result shows that the TiO2in xerogel of the Co,N,P/TiO2/SiO2/CoFe2O4 would change from amorphous to anatase crystal when was heated to 417.7?,and it would change from anatase crystal to rutile type when was heated to 500?1000? The VSM result shows that the Co,N,P/TiO2/SiO2/CoFe2O4 belong to soft magnetic materials,the remanence and coercive force of it is very low.When the Co,N,P/TiO2/SiO2/CoFe2O4 was applied to the photocatalytic,electrocatalytic,photoelectrocatalytic,Fe-assisted photocatalytic,Fe-assisted electrocatalytic and Fe-assisted photoelectrocatalytic degradation of RhB,the results show that all of these degradation reactions followed the pseudo first-degree reaction model,photocatalysis and electrocatalysis have synergistic effect.When Fe was existed in the reactions,the degradation of RhB would be significantly enhanced.When using Co,N,P/TiO2/SiO2/CoFe2O4 as photocatalyst and particle electrode,Fe-assisted photoelectrocatalytic degradation of RhB have been studied.The experimental result shows that under the Na2SO4 concentration as 0.010mol/L,electrolytic voltage as 10V,catalyst dosage as 0.767g/L,initial RhB concentration as 15mg/L and initial pH as 3,the removal rate of Rhodamine B was 98.33%after 50min reaction.