BiOBr掺杂TiO2纳米管阵列光催化降解水中微量双酚A的性能及机理

针对光催化降解水中微量双酚A存在的可见光利用率低、载流子复合效率高和催化剂回收难等问题，本研究采用阳极氧化法和循环浸渍法在钛片上原位制备了BiOBr/TiO₂纳米管阵列(BiOBr/TNTAs)复合光催化剂，使用SEM、XRD和XPS等分析方法对催化剂的形貌和结构进行了表征。结果表明，片层状的BiOBr均匀负载在TNTAs表面，形成了稳定的异质结结构。BiOBr/TNTAs在可见光下对水中微量双酚A的去除率和矿化率明显高于TNTAs，且表现出优异的光催化稳定性。水体中共存的各种阴离子和腐殖酸等会通过竞争活性位点或作为自由基清除剂影响双酚A的去除效果。自由基淬灭结果表明，·OH和h⁺是BiOBr/TNTAs光催化降解双酚A的主要活性物种。光催化活性增强主要归因于BiOBr和TNTAs间p-n异质结的形成，可有效拓展TNTAs的光谱响应范围，从而提高光生电子-空穴的分离效率。

Performance and mechanism of BiOBr modified TiO2 nanotube arrays photocatalytic degradation of trace bisphenol A in water

Due to the low visible light utilization, high photogenerated carriers recombination and difficulties in catalyst recovery in photocatalytic degradation of trace bisphenol A in water, BiOBr/TiO2 nanotube arrays (BiOBr/TNTAs) composite photocatalyst was prepared in situ on titanium plates by anodic oxidation method and cyclic impregnation method. The SEM, XRD and XPS analysis results show that lamellar BiOBr uniformly loaded on the surface of TNTAs and formed a stable heterojunction structure. The removal efficiency and mineralization efficiency of BiOBr/TNTAs were significantly higher than those of TNTAs under visible light. BiOBr/TNTAs shows excellent photocatalytic stability. Various anions and humic acids coexisting in water affected the removal of bisphenol A by competing for active sites or acting as free radical scavenger. The results of free radical quenching experiment show that ·OH and h+ were the main active species for BiOBr/TNTAs photocatalytic degradation of bisphenol A. The enhanced photocatalytic activity was mainly attributed to the formation of p-n heterojunction between BiOBr and TNTAs, which effectively expanded the spectral response range of TNTAs and improved the separation efficiency of photogenerated electron-hole.