ZnO/g-C₃N₄光催化降解亚甲基蓝研究

Photocatalytic Degradation of Methylene Blue by ZnO/g-C₃N₄

摘要: 本文以三聚氰胺为原料，采用水热法及高温煅烧制得管状g-C₃N₄，并以ZnSO₄∙7H₂O为前驱体用沉积沉淀法制得ZnO/g-C₃N₄复合材料。利用表征手段对所制备复合光催化剂的官能团、禁带宽度等进行表征。用LED光源模拟太阳光，将亚甲基蓝(MB)视为模拟污染物，采用紫外可见分光光度计，考察了ZnO/g-C₃N₄复合催化剂对亚甲基蓝(MB)的光催化降解能力。结果表明，复合催化剂中ZnO的含量为30%，回流时间为4 h，回流温度为120℃的条件下制备的复合光催化剂降解效果较好。其他条件相同，用0.1 g∙L⁻¹十二烷基苯磺酸钠作为表面活性剂制备的复合光催化剂降解亚甲基蓝性能显著提高，在光催化反应100 min时可以达到67.53%。

Abstract: g-C₃N₄ with melamine as a raw material was prepared by hydrothermal method and high temperature calcination. The ZnO/g-C₃N₄ composite was precipitated with ZnSO₄·7H₂O as the precursor. The functional group and forbidden band width of the synthesized composite photocatalyst were characterized by means of characterization. The LED light source was used to simulate sunlight, and when methylene blue (MB) was considered as a mock pollutant, the visible photocatalytic degradation ability of ZnO, g-C₃N₄ and ZnO/g-C₃N₄ photocomposite catalysts to methylene blue (MB) was investigated by UV spectrophotometer. The results showed that the composite photocatalyst prepared at 30% mass, reflux time of 4 h and reflux temperature of 120˚C was degraded better. Other conditions are the same; we found that the addition of 0.1 g∙L⁻¹ of sodium dodecyl phenylsulfonate as a surfactant could effectively improve the photocatalytic degradation effect, reaching 67.53% in the photocatalytic reaction at 100 min.