ZnO/g-C_3N_4复合材料的制备及其光催化性能研究

Preparation of ZnO/g-C_3N_4 Composite Photocatalyst with Enhanced Photocatalytic Activity

采用一步法成功制备了氧化锌/石墨相氮化碳(ZnO/g-C_3N_4)复合光催化材料,通过XRD,SEM,TEM,FT-IR和UV-vis DRS对所得样品的微观形貌和吸光特性进行了表征.结果表明,ZnO颗粒均匀分布在片状g-C_3N_4表面上,ZnO/g-C_3N_4最大光吸收边的位置相对于纯相ZnO发生了明显的红移.利用光催化降解甲基橙溶液评估了所得样品的光催化活性,发现ZnO/g-C_3N_4复合材料的光催化效率远高于纯相ZnO和纯相g-C_3N_4,分别达到ZnO的14倍和g-C_3N_4的9倍.复合材料光催化性能得以提升的主要原因有两点:复合样品材料具有比纯相ZnO更大的光吸收范围,提高了太阳光的利用率;ZnO纳米颗粒与g-C_3N_4紧密耦合形成的异质结构有效促进了光生电子-空穴对的分离.

ZnO/g-Ca N4 composite was prepared by one-step calcining, l ne mlcrostructure anu absorption property of the as-prepared samples were characterized by XRD, SEM, TEM, FT-TR, and UV- vis DRS.The results showed that ZnO particles distributed uniformly on the surface of g-Ca N,, and the light absorption edge of the composite had an obvious red shift compared with pure ZnO. Photocatalytie degradation of methyl orange solution experiments was conducted to evaluate photocatalytic activities of the as-prepared samples. The results indicated that ZnO/g-C3 N4 exhibited higher photocatalytic activity than pure ZnO and pure g-CaN4.The photocatalytic efficiency was 14 and 9 times as high as that of ZnO and g-CaN4 ,respectively.The photoeatalytic performance of the composite got promoted mainly due to the formation of heterogeneous structure between ZnO and g-Ca N4, which decreased recombination rate of photo-induced electron-hole pairs.Furthermore,the composite had wider photoabsorption region compared with pure ZnO, which increased utilization rate of solar energy.