Lanthanide metal neodymium-evoked valence electronic and surface microenvironment regulation of Co/N-doped carbon cubes for robust 4-nitrophenol destruction via activating peroxymonosulfate

Metallic Co-based materials are widely recognized as benchmark catalysts for the degradation of organic pollutants. However, they still suffer from relatively low stability and reusability, necessitating the development of efficient regulation strategies. In this study, we propose a unique and effective approach using neodymium (Nd)-mediated valence electronic and surface microenvironment regulation to enhance the catalytic properties of Co/N-doped carbon cubes for the degradation of 4-nitrophenol (4-NP) via peroxymonosulfate (PMS) activation. The strong coordination between the negatively charged organic ligands and positively charged Nd and Co metal ions ensures the intense coupling of Nd and Co sites in the synthesized sample through pyrolysis. Notably, the incorporation of Nd not only modulates the valence electronic properties of Co sites but also increases the defect degree, surface hydrophobicity, and conductivity of the resulting material. These enhancements are responsible for the high-performance degradation of 4-NP through PMS activation. The optimal Nd/[email protected] catalyst achieves a remarkable degradation efficiency of 95 % within 20 min, while also exhibiting enhanced stability and reusability. Furthermore, our developed system demonstrates good tolerances to different conditions, solution pH and inorganic/organic substances. The degradation system involves both radical/non-radical and direct electron transfer pathways. We also unveil the reaction intermediates, their toxicities and the degradation pathways catalyzed by the Nd/[email protected]/PMS system. This study presents a novel strategy utilizing lanthanide metal-evoked regulation to enhance capability of Co-based catalysts for PMS activation towards the degradation of harmful organics.