Fenelon Ernso, Bui Dai-Phat, Tran Huy Hong, You Sheng-Jie, Wang Ya-Fen, Cao Thi Minh, Van Pham Viet
Department of Environmental Engineering, Chung Yuan Christian University, Chung-Li 320, Taiwan.
Department of Civil Engineering, Chung Yuan Christian University, Chung-Li 320, Taiwan.
ACS Omega. 2020 Aug 6;5(32):20438-20449. doi: 10.1021/acsomega.0c02461. eCollection 2020 Aug 18.
The pursuit of robust photocatalysts that can completely degrade organic contaminants with high performance as well as high energy efficiency, simplicity in preparation, and low cost is an appealing topic that potentially promotes photocatalysts for being used widely. Herein, we introduce a new and efficient SnO/BiS/BiOCl-BiOCl (SnO/BiS-Bi25) composite photocatalyst by taking advantage of the robust, simple, and potentially scalable one-pot synthesis, including the hydrothermal process followed by thermal decomposition. Interestingly, we observed the formation of BiOCl-BiOCl (abbreviated as Bi25) heterojunctions derived from reactions between BiS and SnCl·5HO precursor solutions under the hydrothermal condition and thermal decomposition of BiOCl. This Bi25 heterojunction acts as an interface to reduce the recombination of photogenerated electron-hole (e-h) pairs as well as to massively enhance the visible light harvesting, thereby significantly enhancing the photocatalytic degradation performance of the as-prepared composite photocatalyst. In detail, the photocatalytic degradation of Rhodamine B (RhB) activated by visible light using 15% SnO/BiS-Bi25 shows the efficiency of 80.8%, which is superior compared to that of pure BiS (29.4%) and SnO (0.1%). The SnO/BiS-Bi25 composite photocatalyst also presents an excellent photostability and easy recovery from dye for recycling. The trapping test revealed that the photogenerated holes play a crucial factor during the photocatalytic process, whereas superoxide radicals are also formed but not involved in the photocatalytic process. Successful fabrication of SnO/BiS-Bi25 composite photocatalysts via a straightforward method with drastically enhanced photocatalytic performance under visible light activation would be useful for practical applications.
寻求能够高效、高能效地完全降解有机污染物，且制备简单、成本低廉的稳健光催化剂是一个极具吸引力的课题，这有可能推动光催化剂的广泛应用。在此，我们利用稳健、简单且具有潜在可扩展性的一锅法合成，包括水热过程随后的热分解，引入了一种新型高效的SnO/BiS/BiOCl-BiOCl（SnO/BiS-Bi25）复合光催化剂。有趣的是，我们观察到在水热条件下BiS与SnCl·5H₂O前驱体溶液之间的反应以及BiOCl的热分解导致形成了BiOCl-BiOCl（简称为Bi25）异质结。这种Bi25异质结作为一个界面，可减少光生电子-空穴（e-h）对的复合，并大幅增强可见光的捕获，从而显著提高所制备复合光催化剂的光催化降解性能。具体而言，使用15%的SnO/BiS-Bi25在可见光激活下对罗丹明B（RhB）进行光催化降解，效率达到80.8%，优于纯BiS（29.4%）和SnO（0.1%）。SnO/BiS-Bi25复合光催化剂还具有出色的光稳定性，并且易于从染料中回收以进行循环利用。捕获试验表明，光生空穴在光催化过程中起关键作用，而超氧自由基也会形成，但不参与光催化过程。通过一种直接的方法成功制备出在可见光激活下具有大幅增强光催化性能的SnO/BiS-Bi25复合光催化剂，这将对实际应用很有用。
