Construction of Si nanowires/ZnFe2O4/Ag photocatalysts with enhanced photocatalytic activity under visible light and magnetic field

The Si nanowires/ZnFe 2 O 4 /Ag composite photocatalyst is prepared by metal-assisted chemical etching and hydrothermal methods . Photoelectric conversion and photodegradation experiments show that the composite structure offers high photocatalytic performance under visible light. The photocurrent density of Si nanowires/ZnFe 2 O 4 /Ag is 1.76 mA/cm 2 , and the Methyl orange photodegradation rate is 19 % within 90 min. Furthermore, the photocatalytic activity of composite photocatalysts was studied under the magnetic field, which further improves the photocatalytic efficiency significantly. Energy band structure studies revealed that the interfacial contact in the Si nanowires/ZnFe 2 O 4 /Ag increases carrier transfer and charge separation, thereby improving photocatalytic performance. It can be seen from the I-V results that the Si nanowires/ZnFe 2 O 4 /Ag has a negative magnetoresistance . Therefore, in the presence of a magnetic field, photogenerated carriers can be more effectively transferred to the electrode surface to participate in the photocatalytic reaction with improved photocatalytic performance.