(2021) Chemosphere_Cobalt ferrite nanoparticle-loaded nitrogen-doped carbon sponge as a magnetic 3D heterogeneous catalyst for monopersulfate-based oxidation of salicylic acid

Trang N.H., Kwon E., Lisak G., Hu C., Andrew Lin K.-Y.

(Elsevier Ltd) Chemosphere ISSN: 456535 Vol.267 Issue. Article No.128906 DOI: 10.1016/j.chemosphere.2020.128906

As salicylic acid (SAL) is increasingly consumed as a pharmaceutical product, release of SAL into the environment poses threats to ecology because of its low bio-degradability. Thus, SO4^•−-based chemical oxidation processes have been proposed for degrading SAL. Since monopersulfate (MPS) represents a primary reagent for generating SO4^•−, and Co is the most capable metal for activating MPS to generate SO4^•−, C₃O₄ NPs are frequently proposed for activating MPS but they are difficult to recover from water. Thus CoFe₂O₄ is considered as a magnetic alternative to Co₃O₄, and loading of CoFe₂O₄ NPs on substrates could further improve dispersion and avoid aggregation of NPs. Therefore, this study proposes a 3-Dimensional (3D) hierarchical catalyst which is fabricated by loading CoFe₂O₄ NPs on nitrogen-doped carbon sponge (NCS). The NCS is not only adopted as a support for CoFe₂O₄ NPs but also provides additional catalytic sites and enhances catalytic activities of CoFe₂O₄ NPs for MPS activation. As a result, CoFe₂O₄ NPs loaded on NCS (CFNCS) exhibits substantially higher catalytic activities than CoFe₂O₄ NPs and NCS individually with 100% of SAL could be afforded within 30 min. Ea of SAL degradation of 47.4 kJ/mol by CFNCS-activated MPS is also lower than those by other reported catalysts, whereas the RSE was 11.1%, which was also much higher than most of reported values. These features demonstrate that CFNCS is a promising 3D catalyst for enhancing MPS activation to degrade SAL. The findings obtained here are also insightful to develop efficient MPS-activating catalysts for eliminating contaminants. © 2020 Elsevier Ltd

This work is supported by the Ministry of Science and Technology (MOST)(109-2636-E-005-003-), Taiwan, and financially supported by the “Innovation and Development Center of Sustainable Agriculture” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Taiwan.