Li Haibin, Luo Xiang, Long Ziwen, Huang Guoyou, Zhu Ligang
College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Chemistry and Food Science, Yulin Normal University, Yulin 537000, China.
Nanomaterials (Basel). 2022 May 9;12(9):1608. doi: 10.3390/nano12091608.
In this study, n-p Bi2O2CO3/α-Bi2O3 heterojunction microtubes were prepared via a one-step solvothermal route in an H2O-ethylenediamine mixed solvent for the first time. Then, Ag nanoparticles were loaded onto the microtubes using a photo-deposition process. It was found that a Bi2O2CO3/α-Bi2O3 heterostructure was formed as a result of the in situ carbonatization of α-Bi2O3microtubes on the surface. The photocatalytic activities of α-Bi2O3 microtubes, Bi2O2CO3/α-Bi2O3 microtubes, and Ag nanoparticle-loaded Bi2O2CO3/α-Bi2O3 microtubes were evaluated based on their degradation of methyl orange under visible-light irradiation (λ > 420 nm). The results indicated that Bi2O2CO3/α-Bi2O3 with a Bi2O2CO3 mass fraction of 6.1% exhibited higher photocatalytic activity than α-Bi2O3. Loading the microtubes with Ag nanoparticles significantly improved the photocatalytic activity of Bi2O2CO3/α-Bi2O3. This should be ascribed to the internal static electric field built at the heterojunction interface of Bi2O2CO3 and α-Bi2O3 resulting in superior electron conductivity due to the Ag nanoparticles; additionally, the heterojunction at the interfaces between two semiconductors and Ag nanoparticles and the local electromagnetic field induced by the surface plasmon resonance effect of Ag nanoparticles effectively facilitate the photoinduced charge carrier transfer and separation of α-Bi2O3. Furthermore, loading of Ag nanoparticles leads to the formation of new reactive sites, and a new reactive species ·O2− for photocatalysis, compared with Bi2O2CO3/α-Bi2O3.
在本研究中，首次通过在H2O - 乙二胺混合溶剂中一步溶剂热法制备了n - p型Bi2O2CO3/α - Bi2O3异质结微管。然后，采用光沉积法将Ag纳米颗粒负载到微管上。结果发现，由于α - Bi2O3微管表面原位碳酸化，形成了Bi2O2CO3/α - Bi2O3异质结构。基于在可见光照射（λ > 420 nm）下对甲基橙的降解，评估了α - Bi2O3微管、Bi2O2CO3/α - Bi2O3微管以及负载Ag纳米颗粒的Bi2O2CO3/α - Bi2O3微管的光催化活性。结果表明，Bi2O2CO3质量分数为6.1%的Bi2O2CO3/α - Bi2O3表现出比α - Bi2O3更高的光催化活性。用Ag纳米颗粒负载微管显著提高了Bi2O2CO3/α - Bi2O3的光催化活性。这应归因于在Bi2O2CO3和α - Bi2O3的异质结界面处形成的内部静电场，由于Ag纳米颗粒导致了优异的电子传导性；此外，两种半导体与Ag纳米颗粒之间界面处的异质结以及Ag纳米颗粒表面等离子体共振效应诱导的局部电磁场有效地促进了α - Bi2O3光生载流子的转移和分离。此外，与Bi2O2CO3/α - Bi2O3相比，Ag纳米颗粒的负载导致形成了新的反应位点以及用于光催化的新活性物种·O2−。
