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以Bi(NO3)3.5H2O和FeCl3.6H2O为原料、KOH为矿化剂、Tween 80为表面活性剂,采用微波水热法合成BiFeO3粉体。研究了Tween 80含量对BiFeO3粉体形貌、物相及光催化性能的影响,结果表明:在200℃保温1 h,KOH浓度为1.5 mol/L、Tween 80加入体积分数为0～1.7%、Fe与Bi摩尔比为1.0时,合成出单相BiFeO3粉体。当Tween 80加入量小于1.7%时,随Tween 80加入量增加,BiFeO3粉体形貌逐渐变为均匀的毛球状,以此时的粉体作催化剂时,紫外光照射4 h后罗丹明B的降解率从48.92%上升到79.71%;当Tween 80加入量大于1.7%时,制备出BiFeO3–Bi25FeO40复合粉体,以BiFeO3–Bi25FeO40复合粉体、BiFeO3和Bi25FeO40简单混合的粉体作催化剂,紫外光照射4 h后罗丹明B的降解率分别为97.42%与86.73%。以BiFeO3粉体、一次回收的BiFeO3粉体和二次回收的BiFeO3粉体作催化剂时,经紫外光照射4 h后罗丹明B的降解率分别为79.71%、76.78%和68.84%。
BiFeO3 powder was synthesized by microwave hydrothermal method using Bi (NO3) 3.5H2O and FeCl3.6H2O as raw materials, KOH as mineralizer and Tween 80 as surfactant. The effects of Tween 80 content on the morphology, phase and photocatalytic properties of BiFeO3 powder were investigated. The results showed that the KOH concentration was 1.5 mol / L at 200 ℃ for 1 h, the volume fraction of Tween 80 was 0-1.7% Fe and Bi molar ratio of 1.0, the synthesis of single-phase BiFeO3 powder. When the amount of Tween 80 is less than 1.7%, the morphology of BiFeO3 powder becomes uniform with the increase of the amount of Tween 80 powder. When the powder is used as catalyst, the amount of Rhodamine B The degradation rate increased from 48.92% to 79.71%. When the amount of Tween 80 was more than 1.7%, the BiFeO3-Bi25FeO40 composite powders were prepared. The BiFeO3-Bi25FeO40 composite powders, BiFeO3 and Bi25FeO40 powders were used as catalysts, The degradation rates of rhodamine B after irradiation for 4 h were 97.42% and 86.73%, respectively. When biFeO3 powder, once-recovered BiFeO3 powder and twice-recovered BiFeO3 powder were used as catalysts, the degradation rates of rhodamine B were 79.71%, 76.78% and 68.84% after being irradiated with UV light for 4 h, respectively.