ML-WO_(3)/TiO_(2)异质结的制备及其对罗丹明B的光催化降解  

Preparation of ML-WO_(3)/TiO_(2)heterojunction and its photocatalytic degradation of rhodamine B

作　　者：刘静[1] 杨璐冰 李晨 陈永凯 张震 位文华 LIU Jing;YANG Lubing;LI Chen;CHEN Yongkai;ZHANG Zhen;WEI Wenhua(School of Municipal&Environmental Engineering,Shandong Jianzhu University,Jinan 250101,Shandong,China)

机构地区：[1]山东建筑大学市政与环境工程学院,山东济南250101

出　　处：《精细化工》2022年第12期2456-2466,共11页Fine Chemicals

摘　　要：采用空间限域法制备了单层二维WO_(3)纳米片(ML-WO_(3)),然后将其与TiO_(2)复合得到ML-WO_(3)/TiO_(2)异质结,在模拟太阳光下将其用于对罗丹明B(RhB)的光催化降解。ML-WO_(3)/TiO_(2)异质结的组成和光学特性通过SEM、TEM、HRTEM、AFM、XRD、XPS、UV-Vis和PL进行了表征。结果表明,纳米ML-WO_(3)/TiO_(2)克服了纯TiO_(2)带隙宽度较大的缺陷,拓宽了TiO_(2)对可见光的吸收性能。ML-WO_(3)与TiO_(2)之间具有明显的协同效应。活性物种捕获实验表明,·OH和·O_(2)^(–)自由基是RhB降解的主要活性物种。ML-WO_(3)和TiO_(2)之间构建的Z型异质结电荷转移路径能够保证光生载流子的高效分离和电子转移效率。模拟太阳光下20 min内20 mg ML-WO_(3)/TiO_(2)在pH=7条件下对质量浓度为10 mg/L RhB降解率为85.9%,其光催化活性在4次循环实验后仍能接近80%,具有良好的光化学稳定性。通过HPLC-MS检测到RhB降解过程的14种中间产物,推测了RhB可能的降解路径。ML-WO_(3)/TiO_(2)heterojunction was prepared by compounding TiO_(2)with monolayer two-dimension tungsten trioxide nanosheets(ML-WO_(3)),which were obtained via space-confined strategy,and then used for photocatalytic degradation of rhodamine B(Rh B)under simulated sunlight.The composition and optical properties of ML-WO_(3)/TiO_(2)were characterized and analyzed by SEM,TEM,HRTEM,AFM,XRD,XPS,UV-Vis and PL.The results showed that nanosized ML-WO_(3)/TiO_(2)overcame the large band gap defect of pure TiO_(2)and broadened the absorption performance of TiO_(2)to visible light,indicating synergistic effect between ML-WO_(3)and TiO_(2).Moreover,the capture experiments of active species demonstrated that·OH and·O_(2)^(–)free radicals were the main active species for Rh B degradation,and the Z-scheme heterojunction charge transfer pathway constructed between ML-WO_(3)and TiO_(2)could ensure efficient separation of photogenerated carriers and electron transfer efficiency.The degradation rate of Rh B with a mass concentration of 10 mg/L catalyzed by 20 mg ML-WO_(3)/TiO_(2)composites at pH=7 was 85.9%under simulated sunlight for20 min,and the photocatalytic activity of ML-WO_(3)/TiO_(2)composites could still remain 80%after 4 recycles showing good photochemical stability.Fourteen intermediates produced during RhB degradation were detected by HPLC-MS,which helped for the speculation of the possible Rh B degradation pathways.

关 键 词：ML-WO_(3)/TiO_(2) 光催化 Z型异质结 模拟太阳光 罗丹明B 功能材料 

分 类 号：X703[环境科学与工程—环境工程] O643.36[理学—物理化学] O644.1[理学—化学]