Abstract: The supported photocatalysts NiFe 2 O4/g-C3 N4 with different NiFe2 O4 content were synthesized by impregnation method and performed on the photocatalytic degradation of methylene orange ( MO ) under visible-light region.Several techniques, including XRD, FT-IR, N2-adsorption, ICP-IOS SEM, TEM and XPS, were employed to obtain the physical and chemical properties of NiFe 2 O4/g-C3 N4 samples.The results indicate that the supported catalyst NiFe 2 O4/g-C3 N4 exhibited higher photocatalytic activity of MO compared to NiFe 2 O4 and g-C3 N4 .The catalytic activity of NiFe 2 O4/g-C3 N4 sample increased and then decreased with the increasing NiFe 2 O4 doping amount ranged from 0.5wt; to 5. 0wt;, of which the 2-NiFe/CN sample with 2.0wt; NiFe2 O4 loading exhibited the best degradation activity and stability for the photocatalytic degradation of methyl orange (5 mg· L-1 ) under visible light irradiation.It's ascribed to the heterojunction structure of NiFe 2 O4/g-C3 N4 sample formed between narrow energy band (1.5 eV) of NiFe2 O4 and wide energy band (2.7 eV) of g-C3 N4 , which facilities the speed transmission of photoexcited carriers at the interface of NiFe 2 O4 and g-C3 N4 , and enhances the effective separation of electron-hole pairs.

Key words: The supported photocatalysts NiFe 2 O4/g-C3 N4 with different NiFe2 O4 content were synthesized by impregnation method and performed on the photocatalytic degradation of methylene orange ( MO ) under visible-light region.Several techniques, including XRD, FT-IR, N2-adsorption, ICP-IOS SEM, TEM and XPS, were employed to obtain the physical and chemical properties of NiFe 2 O4/g-C3 N4 samples.The results indicate that the supported catalyst NiFe 2 O4/g-C3 N4 exhibited higher photocatalytic activity of MO compared to NiFe 2 O4 and g-C3 N4 .The catalytic activity of NiFe 2 O4/g-C3 N4 sample increased and then decreased with the increasing NiFe 2 O4 doping amount ranged from 0.5wt; to 5. 0wt;, of which the 2-NiFe/CN sample with 2.0wt; NiFe2 O4 loading exhibited the best degradation activity and stability for the photocatalytic degradation of methyl orange (5 mg· L-1 ) under visible light irradiation.It's ascribed to the heterojunction structure of NiFe 2 O4/g-C3 N4 sample formed between narrow energy band (1.5 eV) of NiFe2 O4 and wide energy band (2.7 eV) of g-C3 N4 , which facilities the speed transmission of photoexcited carriers at the interface of NiFe 2 O4 and g-C3 N4 , and enhances the effective separation of electron-hole pairs.