Percivalle Nicolò Maria, Carofiglio Marco, Hernández Simelys, Cauda Valentina
Department of Applied Science and Technology, Politecnico Di Torino, Corso Duca Degli Abruzzi 24, 10129, Turin, Italy.
Discov Nano. 2024 Aug 9;19(1):126. doi: 10.1186/s11671-024-04077-7.
Rhodamine B (RhB) is a harmful dye released by industrial wastewaters, thus necessitating its urgent removal. Advanced oxidation processes constitute promising strategies to purify polluted water. Among others, photocatalysis relies on reactive oxygen species (ROS) produced by photocatalytic particles, typically semiconductors like titania or zinc oxide (ZnO), excited by solar or UV-Vis light. However, their wide band gap limits their catalytic capabilities within the absorption of the UV spectrum and causes fast electron-hole recombination. This study presents novel strategies to overcome these limitations: (i) doping semiconductors to increase photocatalytic efficiency; (ii) sensitization-mediated photocatalysis for visible light activation using chemical moieties to trap dye molecules; (iii) nanosizing the photocatalysts to enhance the surface area. ZnO nanoparticles, doped with iron or gadolinium and capped with oleic acid are here synthesized and tested in RhB dye solutions. Remarkably, the results demonstrate an ultra-fast RhB degradation, driven by oleic acid having crucial role in dye adsorption. The degradation mechanisms, including ROS-induced N-deethylation and xanthene group cleavage, are also unraveled. These findings underscore the efficacy of the proposed semiconductor photocatalyst design, highlighting a significant advancement with extensive potential applications in wastewater remediation. This innovative approach paves the way for more efficient and practical solutions to combat industrial dye pollution.
罗丹明B（RhB）是工业废水中排放的一种有害染料，因此急需将其去除。高级氧化工艺是净化受污染水的有前景的策略。其中，光催化依赖于光催化颗粒产生的活性氧（ROS），典型的是二氧化钛或氧化锌（ZnO）等半导体，由太阳光或紫外-可见光激发。然而，它们的宽带隙限制了其在紫外光谱吸收范围内的催化能力，并导致快速的电子-空穴复合。本研究提出了克服这些限制的新策略：（i）掺杂半导体以提高光催化效率；（ii）使用化学基团捕获染料分子，通过敏化介导的光催化实现可见光活化；（iii）将光催化剂纳米化以增加表面积。本文合成了掺杂铁或钆并以油酸封端的ZnO纳米颗粒，并在RhB染料溶液中进行了测试。值得注意的是，结果表明油酸在染料吸附中起关键作用，驱动了RhB的超快速降解。还揭示了包括ROS诱导的N-脱乙基化和呫吨基团裂解在内的降解机制。这些发现强调了所提出的半导体光催化剂设计的有效性，突出了在废水修复中具有广泛潜在应用的重大进展。这种创新方法为对抗工业染料污染提供了更高效、实用的解决方案铺平了道路。
