Two-dimensional MBene combined with cobalt nanoparticles enabling highly efficient peroxymonosulfate activation for ornidazole degradation

Two-dimensional (2D) MXene materials have been recognized as a new candidate for the development of robust catalytic systems to promote the peroxymonosulfate (PMS)-based Fenton-like reaction towards organic pollutant elimination in water, however, there is an ongoing demands for the discovery of MXene analogs to enrich and understand their functions in PMS catalysis. Herein, we introduce a new 2D transition metal boride (MBene, MoAl 1-x B) with a structure similar to MXene to combine with cobaltic nanocatalyst, achieving highly efficient PMS catalysis. The resulting Co-MoAl 1-x B catalyst exhibits the impressive catalytic performance in activating PMS for ornidazole (ONZ) degradation, delivering a first-order kinetic constant of 0.4261 min −1 . In-depth experimental investigations using the combined spectroscopic, electrochemical and quenching tests demonstrate that the sulfate radical (SO 4 •− ), singlet oxygen ( 1 O 2 ) and electron transfer simultaneously dominate the radical/nonradical pathways to mediate the ONZ degradation. This study provides a new catalytic system and sheds light on the fundamental understanding the role of MBene for efficient PMS catalysis.