Novel multifunctional NiFe 2 O 4 /ZnO hybrids for dye removal by adsorption, photocatalysis and magnetic separation

• DOI: 10.1016/j.apsusc.2016.02.025
• Publication Date: 2016-02-17T17:41:54Z
• Authors: Hua-Yue Zhu; Ru Jiang; Yong-Qian Fu; Rong-Rong Li; Jun Yao; Sheng-Tao Jiang
• Keywords: Congo red; Magnetic separation

Abstract Novel multifunctional NiFe 2 O 4 /ZnO hybrids were prepared by a hydrothermal method and their physicochemical properties were characterized by XRD, SEM, TEM, TGA, VSM, BET and UV–vis DRS. The adsorption and photocatalytic performance of NiFe 2 O 4 /ZnO hybrids were systematically investigated using congo red as a model contaminant. With the introduction of NiFe 2 O 4 , NiFe 2 O 4 /ZnO hybrids can absorb the whole light from 300 nm to 700 nm. The adsorption capacity (221.73 mg g −1 ) of NiFe 2 O 4 /ZnO hybrids is higher than those of NiFe 2 O 4 , ZnO and mechanically mixed NiFe 2 O 4 /ZnO hybrids. The removal of congo red solution (20 mg L −1 ) by NiFe 2 O 4 /ZnO hybrids was about 94.55% under simulated solar light irradiation for 10 min. OH and h + play important roles in the decolorization of congo red solution by NiFe 2 O 4 /ZnO hybrids under simulated solar light irradiation. The decolorization efficiency of congo red solution is 97.23% for the fifth time by NiFe 2 O 4 /ZnO hybrids under simulate solar light irradiation, indicating the high photostability and durability. NO 3 − and Cl − anions which are ubiquitous components in dye-containing wastewater have negligible influence on the effectiveness of NiFe 2 O 4 /ZnO hybrids. Moreover, the magnetic NiFe 2 O 4 /ZnO hybrids can be easily separated from the reacted solution by an external magnet.