【摘要】 用水热法制备系列p-NiFe₂O₄/n-CdS光催化剂,通过固定床微反应器中可见光催化降解亚甲基蓝对p-NiFe₂O₄/n-CdS的光催化活性进行评价,并对光催化活性提高的机制和反应条件对降解性能的影响进行分析。结果表明:p型和n型两种窄带隙半导体复合可提高光吸收率和光生电荷的分离效率,从而提高光催化活性。固定床微反应器中亚甲基蓝光催化降解过程符合一级动力学反应模型;与光催化剂表面吸附性能相比,光生电荷的分离效率是影响固定床微反应器中可见光催化降解亚甲基蓝性能的主要因素。在NiFe₂O₄的复合质量分数为0.14%、流速为0.4 mL/h、亚甲基蓝的初始质量浓度为10 mg/L、pH=6时,固定床微反应器中可见光催化降解亚甲基蓝的降解率最高。更多还原

【Abstract】 A series of p-NiFe₂O₄/n-CdS photocatalysts were prepared by a hydrothermal method. The photocatalytic activity of p-NiFe₂O₄/n-CdS was evaluated by photocatalytic degradation of methylene blue in a fixed-bed microreactor, and the mechanism of the increase in photocatalytic activity and the effect of reaction conditions on degradation were analyzed. Results showed that combined p-type narrow bandgap semiconductor and n-type one could improve the light absorption and photo-generated charge separation efficiency, which increased the photocatalytic activity. The process of methylene blue catalytic degradation in a fixed-bed microreactor could be described by the first-order kinetic model. Compared with the photocatalytic surface adsorption performance, the separation efficiency of photogenerated charge was the main factor that affected the performance of degradation of methylene blue in a fixed-bed microreactor under visible light irradiation. When the amount of NiFe₂O₄ was 0.14%, the flow rate was 0.4 mL/h, the initial concentration of methylene blue was 10 mg/L, and the pH was 6, the degradation of methylene blue in the fixed-bed microreactor was under visible light irradiation at the highest level.更多还原