Department of Chemical Engineering, National Institute of Technology Karnataka (NITK) Surathkal, Mangalore, Karnataka, 575025, India.
Environ Sci Pollut Res Int. 2023 Feb;30(10):25402-25416. doi: 10.1007/s11356-021-17636-7. Epub 2021 Nov 23.
A novel BiOY (Y = Br/Cl) heterojunction nanocatalyst was synthesised chemically and compared with three different BiOX (X = Br/Cl/I) nanocatalysts as well as a physical admixture of BiOBr/BiOCl catalysts in the photocatalytic degradation of malachite green dye wastewater under solar irradiation in both suspended and immobilised forms using polysulfone as the substrate. Catalyst characterisation was done by a particle size analyser, SEM/EDX, XRD, FTIR, and DRS. In the suspended form, BiOBr showed 100% degradation within 70 min, BiOCl showed 99.3%, and BiOI showed 11.2% degradation within 120 min, and it is found to follow pseudo-first-order kinetics. In the immobilised form, BiOBr showed 89.1%, and BiOCl showed 83.4% degradation within 180 min under sunlight. The degradation measured by TOC reduction for these catalysts in suspended form was 67.4%, 57%, and 40%, affirming BiOBr as the best among these catalysts. The performance of the immobilised chemically synthesised BiOY and physical admixture catalysts were 88% and 14%, respectively. The enhanced activity in the chemically synthesised immobilised BiOBr/Cl catalyst can be attributed to the effective charge separation at the heterojunction interface. These photocatalysts are very active under solar light and hence suitable for the efficient degradation of other recalcitrant organic contaminants.
一种新型的 BiOY（Y = Br/Cl）异质结纳米催化剂通过化学方法合成，并与三种不同的 BiOX（X = Br/Cl/I）纳米催化剂以及 BiOBr/BiOCl 催化剂的物理混合物进行比较，在悬浮和固定化形式下，使用聚砜作为基底，在太阳照射下，对孔雀石绿染料废水进行光催化降解。通过粒径分析仪、SEM/EDX、XRD、FTIR 和 DRS 对催化剂进行了表征。在悬浮状态下，BiOBr 在 70 分钟内降解率达到 100%，BiOCl 降解率达到 99.3%，BiOI 降解率达到 11.2%，反应遵循准一级动力学。在固定化状态下，BiOBr 和 BiOCl 在阳光下 180 分钟内的降解率分别为 89.1%和 83.4%。通过 TOC 减少测量，这些催化剂在悬浮状态下的降解率分别为 67.4%、57%和 40%，证明 BiOBr 是这些催化剂中最好的一种。化学合成的固定化 BiOY 和物理混合物催化剂的性能分别为 88%和 14%。化学合成的固定化 BiOBr/Cl 催化剂中有效电荷分离在异质结界面上，这导致其活性增强。这些光催化剂在太阳光下非常活跃，因此适用于其他难降解有机污染物的有效降解。
