可见光响应型Ag/Ag_3PO_4复合光催化剂的制备及其光催化性能

Preparation and photocatalytic performance of visible-light-driven Ag/Ag_3PO_4 complex photocatalysts

以AgNO_3和Na_2HPO_4为原料,采用液相沉淀结合光还原法合成了Ag/Ag_3PO_4复合光催化材料,采用XRD、SEM、UV-vis DRS及光降解亚甲基蓝实验对样品的晶相结构、表面形貌、光吸收性能及光催化性能进行了表征,结果表明,所得Ag/Ag_3PO_4样品呈类球状,尺寸分布均匀,粒径约为0. 2μm,样品中Ag_3PO_4呈体心立方相结构,Ag的掺入,改变了Ag_3PO_4的晶格参数,(210)及(211)晶面衍射峰发生明显红移;同时Ag的掺入使其在Ag_3PO_4晶格内部形成掺杂能级,窄化了Ag_3PO_4的能带结构,拓宽了材料的可见光响应范围。以氙灯为光源,光照90min时,样品对MB表现出较好的光催化降解效果,降解率可达96. 57%;且重复使用5次后,Ag/Ag_3PO_4样品对MB的降解率仍然保持在80%左右,明显优于纯Ag_3PO_4。

Using AgNO 3 and Na 2HPO 4 as raw materials,Ag/Ag 3PO 4 photocatalysts were prepared via liquid deposition and photo-reduction method.The phase crystallinity,surface morphology,photo-absorbance and photocatalytic performance of synthesized samples were characterized by XRD,SEM,UV-vis and photocatalytic degradation of MB.The results indicated that,the obtained Ag/Ag 3PO 4 photocatalysts had sphere-like structure with uniform size.The XRD patterns indicated that Ag/Ag 3PO 4 consisted of body-centered cubic phase.Ag atoms were doped into the Ag 3PO 4 lattice,which resulted in a shift of(210)and(211)lattice plane.Furthermore,introduction of Ag into Ag 3PO 4 not only narrowed the bandgap of Ag 3PO 4 but also extended the absorption range of visible light.Photocatalytic results showed that under the visible light irradiation,Ag/Ag 3PO 4 samples showed the highest photocatalytic activity,and 96.57%of MB could be degraded within 90 min.Furthermore,the photocatalytic efficiency of Ag/Ag 3PO 4 samples still remained about 80%after being reused for five times.