Zhang Feihu, Xiao Xinyan, Xiao Yu
School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab of Green Chemical Product Technology, South China University of Technology, Guangzhou 510640, China.
Department of Mechanical Engineering, University of Manitoba, Winnipeg, R3T 2N2, Canada.
Dalton Trans. 2022 Jul 26;51(29):10992-11004. doi: 10.1039/d2dt01489k.
A novel type II BiOCl/CAU-17 2D/2D heterostructure photocatalyst was synthesized by growth of ultrathin BiOCl on the surface of CAU-17 nanorods through a solvothermal process. The 2D/2D heterostructures endow the BiOCl/CAU-17 heterojunction with a large specific surface area and tight interfacial contact, which can provide sufficient channels for carrier migration. The introduction of CAU-17 can enhance the light absorption ability of BiOCl/CAU-17 photocatalysts. Furthermore, the staggered type II heterostructure energy band alignment formed between BiOCl and CAU-17 can promote the separation of photoexcited carriers. The improved performance for carrier migration and light absorption was evaluated by SEM, TEM, BET, EIS, and DRS tests. Transient photocurrent response and photoluminescence tests confirmed the improvement in separating photoexcited carriers. The optimal 70% BiOCl/CAU-17 sample exhibited the highest photocatalytic degradation efficiency of 96.3% for RhB and 85.5% for TC, under 90 min of simulated solar light irradiation. Its apparent first-order rate constant values are 0.02947 and 0.01955 min, respectively, being 48.31 and 19.75 fold higher than those of CAU-17, and 7.61 and 1.84 fold higher than those of BiOCl. The free radical scavenging experiment results showed that h and ˙O are the prime active species during the photodegradation process. Hence, a possible photocatalytic mechanism of the type II BiOCl/CAU-17 heterojunction was proposed.
通过溶剂热法在CAU-17纳米棒表面生长超薄BiOCl，合成了一种新型的II型BiOCl/CAU-17二维/二维异质结构光催化剂。二维/二维异质结构赋予BiOCl/CAU-17异质结较大的比表面积和紧密的界面接触，可为载流子迁移提供充足的通道。CAU-17的引入可增强BiOCl/CAU-17光催化剂的光吸收能力。此外，BiOCl与CAU-17之间形成的交错型II型异质结构能带排列可促进光生载流子的分离。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、比表面积分析仪（BET）、电化学阻抗谱（EIS）和漫反射光谱（DRS）测试评估了载流子迁移和光吸收性能的改善。瞬态光电流响应和光致发光测试证实了光生载流子分离的改善。在模拟太阳光照射90分钟的条件下，最佳的70% BiOCl/CAU-17样品对罗丹明B（RhB）的光催化降解效率最高，为96.3%，对四环素（TC）的光催化降解效率为85.5%。其表观一级速率常数分别为0.02947和0.01955 min⁻¹，分别比CAU-17高48.31倍和19.75倍，比BiOCl高7.61倍和1.84倍。自由基清除实验结果表明，h⁺和˙O⁻是光降解过程中的主要活性物种。因此，提出了II型BiOCl/CAU-17异质结可能的光催化机理。
