摘要：

采用简单的水热法成功合成了钼酸铋（Bi₂MoO₆）光催化剂，通过XRD、FESEM对光催化剂的晶体结构和形貌进行分析。在光照射条件下，研究了Bi₂MoO₆耦合过硫酸盐（PS）降解水中亚甲基蓝（MB）的效果，分别考察过硫酸盐浓度、催化剂投加量、初始pH、共存阴离子和腐殖酸对MB降解效果的影响。结果表明，PS浓度为2 mmol/L、Bi₂MoO₆投加量为0.6 g/L、pH为11时，光照60 min后MB降解率可达99%。中性和碱性pH条件下MB均可有效降解，碱性初始pH更有利于反应体系降解MB。Cl-对MB的降解有促进作用，而NO₃^-、CO₃^2-、腐殖酸均对MB的降解有抑制作用。自由基猝灭实验结果表明，光/Bi₂MoO₆/PS体系中的主要活性物种为h⁺、SO₄^·-、·OH。研究结果可为探索新型非均相催化剂协同PS降解染料废水提供一定应用参考。

关键词: 光催化, 过硫酸盐, 钼酸铋, 亚甲基蓝

Abstract:

The bismuth molybdate photocatalyst(Bi₂MoO₆) was successfully synthesized by a simple hydrothermal method. The crystal structure and morphology of the catalyst were studied by XRD and FESEM. Under light irradiation, the degradation of methylene blue(MB) in water by Bi₂MoO₆ coupled with persulfate(PS) was studied. The effects of PS concentration, photocatalyst dosage, initial pH, coexisting anions and humic acid were investigated separately. The results showed that under the condition of PS concentration 2 mmol/L, the dosage of Bi₂MoO₆ 0.6 g/L, and the pH 11, MB could degrade 99% after 60 minutes of light irradiation. In neutral and alkaline initial pH, MB could be effectively degraded. The alkaline initial pH was more beneficial for the degradation of MB in the reaction system. Clpromoted the degradation of MB, while NO₃^-, CO₃^2- and humic acid all inhibited the degradation of MB. Free radical quenching experiments proved that the main reactive species in the reaction system are h⁺, SO₄^·- and ·OH. The results can provide reference for exploring the synergistic degradation of dye wastewater by new heterogeneous catalysts with persulfate.

Key words: photocatalysis, persulfate, Bi₂MoO₆, methylene blue

中图分类号: 

• X703