Ultrafast degradation of organic dyes via PMS activation by CNT-loaded MOF-derived Co nanoparticles

The research team has developed an innovative solution to address the persistent challenge of organic dye pollution in wastewater. While PMS-based advanced oxidation shows promise for degrading these hard-to-remove contaminants, its practical application has been hindered by the limitations of existing catalysts—particularly metal–organic frameworks (MOFs), which suffer from nanoparticle aggregation and difficult recovery. The team's breakthrough composite material, carbon nanotube (CNTs)-supported MOF-derived cobalt nanoparticles (Co@CNTs-800), overcomes these barriers by enabling highly efficient, rapid, and reusable activation of PMS for organic dye degradation.

The catalyst was synthesized by transforming a Co-MOF@CNTs precursor into a porous structure where cobalt nanoparticles are embedded within defective CNTs. This design not only prevents particle agglomeration and enhances mass transfer but also allows convenient magnetic recovery. In performance tests, the Co@CNTs-800/PMS system completely degraded high-concentration Rhodamine B (RhB) within just four minutes.

Notably, the catalyst maintained high activity across a broad pH range (4–10) and in the presence of common interfering substances such as chloride, nitrate, and natural organic matter. It also demonstrated excellent reusability, retaining its performance over six consecutive cycles. Experiments using real water samples from the Huangpu River and Suzhou Creek further confirmed its practical applicability. Mechanistic studies revealed that the degradation process follows a non-radical pathway dominated by singlet oxygen (¹O₂), which offers high selectivity and strong anti-interference capability. The degradation pathways of RhB were further clarified through liquid chromatography–mass spectrometry (LC–MS) and density functional theory (DFT) calculations.

This research overcomes key limitations of MOF-derived catalysts and provides an efficient, sustainable solution for treating hard-to-degrade organic wastewater. With its outstanding catalytic performance, ease of recovery, and adaptability to complex water environments, the Co@CNTs-800 system represents a significant step toward real-world application of advanced oxidation technologies.

The research was conducted in collaboration between the University of Shanghai for Science and Technology and the University of Science and Technology Hong Kong. This work is supported by the National Key Research and Development Program of China (No. 2021YFA1200404), the National Natural Science Foundation of China Projects (No. 12374214), and sponsored by Shanghai Rising-Star Program (23QA1404200). Grateful acknowledgment is made to Yangtze River 3D Scientific Computing Center for providing computational support. The authors would like to thank “Center for Instrumental Analysis, University of Shanghai for Science and Technology (https://sysjc.usst.edu.cn/lab/webindex/index.do)”.

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.