Synthesis And Performance Of Visible-Light-Induced Magetic Catalyst Mn_1-xZn_xFe₂O₄/BiVO₄ With The Loading Of RGO Or Ag

Semiconductor photocatalysts have attracted more attention due to the excellent properties in pollutants degradation and energy conversion.BiVO₄ has proven to be a suitable candidate for the photodegradation organic pollutants.However,due to the weak adsorption ability,difficulty in migration of photogeneration electrons and holes and separating from the water, its practical application receives great limits.So, this paper focused on modifying BiVO₄ by loading RGO or Ag, immobilizing the photocatalyst on the magnetic substrate at the same time to prepare composite magnetic photocatalyst Mn_1-xZn_xFe₂O₄/BiVO₄/X（X=RGO,Ag）,in order to enhance the photocatalytic activity under visible light and improve the efficiency of separation and recycling.Mn_1-xZn_xFe₂O₄ was prepared by chemical co-precipitation, Mn_1-xZn_xFe₂O₄/BiVO₄ was fabricated with the dip-roasting method, Mn_1-xZn_xFe₂O₄/BiVO₄/RGO（MBR） was synthesized successfully through the thermal reduction way. XRD showed that the as-synthesized BiVO₄ was monoclinic crystal system,the introduction of Mn_1-xZn_xFe₂O₄ did not change the structure of BiVO₄.The relatively low ratio of ID/IG of RGO in Raman spectra showed sp2 carbon skeleton of RGO existing in MBR stability and GO was effectively reduced to RGO. VSM tests showed Ms of MBR is 8.21emug-1 and Ms did not significantly reduce after 5 times recycling. EIS results showed that the charge transfer impedance value was decreased.Photocatalytic results showed the degradation rate of MBR reached 96% within 1.5h.The active substances capture experiment showed that O₂?- played the main role in the process of photocatalytic in MBR.Mn_1-xZn_xFe₂O₄/BiVO₄/RGO（MBR） was synthesized successfully through a simple in situ wet chemistry method. XPS results showed that the appearance of Ag3 d characteristic peak, indicating that the presence of Ag in MBA. TEM results showed that BiVO₄ coated on the surface of Mn_1-xZn_xFe₂O₄, a small amount of granular Ag particles dispersed on the spherical surface of the catalyst.UV-vis DRS results showed that the absorption edge of MBA had a larger red shift, the estimated Eg was 2.17 eV.The degradation rate of MBA was 96% within 60 min, the recovery rate was not less than 89%, the degradation rate could reach 94% after 5 times recycle.