g-C3N4/ZnO复合材料的制备、表征及可见光催化性能

Prepartion, Characterization and Their Photocatalytic Activities of g-C3N4/ZnO Composites

摘要:

以一步法原位合成了g-C3N4/ZnO异质结复合材料，评价其在可见光下降解亚甲基蓝（MB）的光催化活性，并探讨了g-C3N4/ZnO的光催化机制。运用XRD、FT-IR、SEM和UV-Vis DRS对所合成的复合材料进行表征。结果表明，经复合后g-C3N4和ZnO紧密结合，构建了异质结，提高了光生电子-空穴的分离效率，并且在可见光区表现出较强的光响应性；当g-C3N4的质量分数为19%时，复合材料降解MB的反应速率常数为0.0206min-1，是纯g-C3N4的3.8倍。催化剂重复使用5次，仍保持较高的催化活性。

Abstract:

g-C3N4/ZnO heterojunction composites were in situ prepared through the one-pot approach. The photocatalytic activities of the samples were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation and the mechanism of g-C3N4/ZnO photocatalytic reaction was investigated. XRD, FT-IR, SEM and UV-Vis DRS were used to characterize the obtained composites. The results show that the heterojunctions are formed by the tight coupling between g-C3N4 and ZnO, which improves the separation efficiency of electron-hole pairs and have stronger light response in visible region. With the optimal g-C3N4 mass fraction of 19%, the catalytic reaction kinetic constants of MB solution degradation was 0.0206min-1, which was 3.8 times that of pure g-C3N4. The regenerated catalyst still kept good catalystic performance after recycling 5 times.