pH值对化学沉淀法制备Ag_2CrO_4纳米晶的结构和光催化性能的影响

Influence of pH Value on the Structure and Photocatalytic Properties of Ag_2CrO_4 Nanocrystals Prepared via Chemical Precipitation Method

以AgNO3、Na2CrO4为原料,采用化学沉淀法成功制备出了鹅卵石结构的Ag2CrO4纳米晶。采用X-射线衍射仪（XRD）、扫描电子显微镜（SEM）、紫外-可见光谱仪等分别对所得产物的物相、形貌及光学性能进行表征,研究了不同pH对Ag2CrO4纳米晶的结构及可见光催化性能的影响。结果表明：在反应体系pH为3~6范围内,均可以制备出纯相的鹅卵石结构的Ag2CrO4纳米晶;pH=3时所得产物在可见光照射下,对罗丹明B（RhB）的催化降解效果最好,光照140min后降解率可达到93%。

Ag2CrO4 nanocrystals with pebbles structure were successfully synthesized via chemical precipitation method,using AgNO3 and Na2CrO4 as raw materials. The phase composition,morphologies and photocatalytic performances of the as-prepared samples were characterized by XRD（ X-ray diffractometer）,SEM（ Scanning electron microscope） and Ultraviolet-visible Absorption Spectroscopy,recpectively. The influence of p H value on the structure and photocatalytic properties of the products were investigated. The results show that the pure phase of Ag2CrO4 nanocrystals with pebbles structure have been successfully prepared at the pH value range from 3 to 6. The Ag2CrO4nanocrystals prepared at pH= 3 exhibit a high photocatalytic properties to Rhodamine B（ Rh B）,which degradation rate reaches 93% under visible-light irradiation for 140 min.