Ruta Vincenzo, Sivo Alessandra, Bonetti Lorenzo, Bajada Mark A, Vilé Gianvito
Department of Chemistry, Materials, and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, MilanoIT-20133, Italy.
ACS Appl Nano Mater. 2022 Oct 28;5(10):14520-14528. doi: 10.1021/acsanm.2c02859. Epub 2022 Oct 14.
The development of efficient catalysts is a highly necessary but challenging task within the field of environmental water remediation. Single-atom catalysts are promising nanomaterials within this respect, but in-depth studies encompassing this class of catalysts remain elusive. In this work, we systematically study the degradation of gemfibrozil, a persistent pollutant, on a series of carbon nitride photocatalysts, investigating both the effect of (i) catalyst textural properties and (ii) metal single atoms on the contaminant degradation. Tests in the absence of the catalyst result in negligible degradation rates, confirming the stability of the contaminant when dispersed in water. Then, photocatalytic tests at optimal pH, solvent, and wavelength reveal a correlation between the support surface area and the degradation. This points to the role of carbon nitride surface nanostructure on gemfibrozil degradation. In particular, the use of silver on mesoporous carbon nitride single-atom catalyst (Ag@mpgCN) leads to an unprecedented degradation of gemfibrozil (>90% within 60 min). The possible degradation intermediates and products were identified by mass spectrometry and were inert by cytotoxicity evaluation. We anticipate that, with further refinement and customization, the carbon nitride catalysts reported herein may find broad applications for light-driven degradation of other contaminants of emerging concern.
开发高效催化剂是环境水修复领域一项极为必要但又具有挑战性的任务。单原子催化剂在这方面是很有前景的纳米材料，但对这类催化剂的深入研究仍然难以捉摸。在这项工作中，我们系统地研究了吉非罗齐（一种持久性污染物）在一系列氮化碳光催化剂上的降解情况，考察了（i）催化剂结构性质和（ii）金属单原子对污染物降解的影响。在无催化剂条件下的测试结果显示降解率可忽略不计，这证实了该污染物分散在水中时的稳定性。然后，在最佳pH值、溶剂和波长下进行的光催化测试揭示了载体表面积与降解之间的相关性。这表明氮化碳表面纳米结构在吉非罗齐降解中所起的作用。特别是，在介孔氮化碳单原子催化剂（Ag@mpgCN）上使用银导致了前所未有的吉非罗齐降解（60分钟内>90%）。通过质谱鉴定了可能的降解中间体和产物，并且通过细胞毒性评估表明它们是惰性的。我们预计，随着进一步的优化和定制，本文报道的氮化碳催化剂可能会在光驱动降解其他新出现的关注污染物方面得到广泛应用。
