Synergized selenium-vacancy heterogeneous interface and carbon nanotubes for insight into efficient oxidation of pollutants via photocatalytic peroxymonosulfate activation

Advanced strategies for enhancing catalytic performance of catalysts include multi-metal active site exposure, vacancy growth and electronic structure optimization. Here, carbon nanotube-loaded CoSe2/FeSe2 catalysts (Co/Fe-CNT) with multiphase boundaries and embedded selenium vacancies (VSe) were prepared using a one-step hydrothermal method. The catalysts feature unique electronic structures and abundant active sites, and were found to exhibit unexpectedly high activity and stability in photocatalytic mediated sulphate radical (SR-photo) system, with impressive oxidation capacity for complex matrix polluted water. The spontaneously formed internal electric field strongly promoted charge transport and significantly enhanced the photocatalytic property. The VSe formed at the heterogeneous interface could modulate the surface electronic structure and accelerate the redox cycling of transition metals, thereby accelerating the production of reactive oxygen species and boosting the efficiency of contaminant degradation. This work provides guidance for the design of high-performance catalysts for VSe engineering and expands their potential for application in wastewater purification.