BiOCl/g-C_(3)N_(4)-Br光催化降解罗丹明B

Photocatalytic degradation of RhB by BiOCl/g-C_(3)N_(4)-Br

采用原位生长法制备了二元异质结光催化剂BiOCl/g-C_(3)N_(4)-Br,运用多种技术手段对其进行了表征,考察了BiOCl/g-C_(3)N_(4)-Br在模拟可见光照射下对罗丹明(RhB)的光催化降解性能。表征结果显示,BiOCl附着在g-C_(3)N_(4)-Br表面,二者之间形成了Z-scheme异质结。实验结果表明:BiOCl/g-C_(3)N_(4)-Br催化剂比g-C_(3)N_(4)-Br和BiOCl具有更高的光催化活性,在RhB质量浓度20 mg/L、BiOCl/2%-g-C_(3)N_(4)-Br(g-C_(3)N_(4)-Br质量分数为2%)加入量0.5 g/L的条件下,经日光灯(14 W)照射90 min后,RhB去除率可达98%;经过4次循环实验后,RhB去除率从98%逐渐降低至90%,表现出良好的稳定性和可重复利用性。BiOCl/2%-g-C_(3)N_(4)-Br光催化降解RhB过程中发生的氧化还原反应分别在BiOCl和g-C_(3)N_(4)-Br的表面进行,BiOCl与g-C_(3)N_(4)-Br之间高度紧密的接触面形成了Z-scheme异质结,实现了电子和空穴的快速分离,降低了二者在催化剂内部的复合速率,提高了催化性能。

A binary heterojunction photocatalyst,BiOCl/g-C_(3)N_(4)-Br,was synthesized by in-situ growth method and characterized by XRD,SEM,FTIR,XPS,and UV-vis DRS.The photocatalytic degradation activity of BiOCl/g-C_(3)N_(4)-Br to RhB under simulated visible light irradiation was investigated.The experimental results show that:Compared to g-C_(3)N_(4)-Br and BiOCl alone,BiOCl/g-C_(3)N_(4)-Br exhibits significantly improved photocatalytic activity,and under the conditions of RhB mass concentration 20 mg/L,BiOCl/2%-g-C_(3)N_(4)-Br amount 5 g/L,fluorescent lamp power 40 W,and irradiation time 90 min,the RhB removal rate can reach 98%;After 4 cycles of reusing,the RhB removal rate gradually decreases from 98%to 90%,demonstrating good stability and reusability of the photocatalyst.The oxidation-reduction reactions in the photocatalytic degradation process occur on the surface of BiOCl and g-C_(3)N_(4)-Br,respectively.The Z-scheme heterojunction formed on the highly compact interface between BiOCl and g-C_(3)N_(4)-Br achieves rapid separation of electrons and holes and reduces their recombination rate inside the catalyst,thereby enhancing the catalytic performance.