Ag/Bi2S3/Bi2WO6复合催化剂合成及光催化性能研究

Synthesis and Photocatalytic Performace of Ag/Bi_2S_3/Bi_2WO_6 Composite Photocatalyst

以硝酸铋、钨酸钠和硫脲为起始原料,采用一步水热法成功合成Bi_2S_3/Bi2WO6光催化剂,采用光还原法在Bi_2S_3/Bi2WO6表面沉积贵金属Ag。采用XRD、XPS、FESEM、TEM和UV-Vis-DRS等手段对Bi_2S_3/Bi2WO6和Ag/Bi_2S_3/Bi2WO6进行表征,并以罗丹明B和苯酚作为模型污染物对其光催化性能进行研究。结果证明,耦合Bi_2S_3可以提高Bi2WO6催化剂的光催化活性,Ag沉积使得其光催化性能进一步提高,且Ag的沉积量与催化剂的活性关系密切,其中5%Ag/Bi_2S_3/Bi2WO6的光催化效果最好。此外,结合活性物种检测和能带结构分析,对Ag/Bi_2S_3/Bi2WO6的光催化活性增强机理进行了分析。

Using Bi（NO3）3· 5H2O , Na2WO4 · 2H2O and thiourea as starting materials, Bi2S3/B i2W06 was synthesized by one-step hydrothermal method. Ag was deposited on the surface of Bi2S3/Bi2W06 via a following facile photo-reduced method. All the as-prepared catalysts were characterized by XRD, XPS, FESEM, TEM and UV-Vis-DRS. Rhodamine B and Phenol were selected as model pollutants to evaluate the photocatalytic activities of samples. The Bi2S3 coupling significantly enhance the photocatalytic activity of Bi2W06. The results show that Ag loading further improve the photocatalytic activity of Bi2S3/Bi2WO6 composite, the content of loading silver has an impact on the catalytic activity of Bi2S3/Bi2W06 composite.The 5% Ag/Bi2S3/Bi2WO6 sample exhibite the best photocatalytic activity in photodegradation of phenol. In addition, the mechanism for the enhancement of the photocatalytic activity of Ag/Bi2S3/Bi2WO6 was also investigated based on the determination of free radical species and its energy structure of Ag/Bi2S3/Bi2WO6.