Synthesis and photocatalytic properties of BiOI/NiFe2O4 composites

BiOI/NiFe2O4 composite is a novel type of photocatalyst, which has good photocatalytic activity and magnetic property. In this paper, BiOI/NiFe2O4 composites with different molar ratios were synthesized by hydrothermal approach. The as-prepared samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and UV–vis diffuse reflectance (UV–vis DRS) to study the crystalline structures, morphologies and optical properties. The photocatalytic performance of BiOI/NiFe2O4 composites were investigated through the experiments of photocatalytic degradation of methyl orange (MO), and the results showed that the photocatalytic activity of 20% BiOI/NiFe2O4 was the highest. It was worth mentioning that the recovery of the used composites can be performed easily owing to the good magnetic property. Terephthalic acid photoluminescence (TA-PL) probing and trapping agent experiments demonstrated that photogenerated hole h+ was the main active oxidation species and played a major role, while OH and played secondary roles during the photocatalytic process.