Hierarchical Co-Fe layered double hydroxides (LDH)/Ni foam composite as a recyclable peroxymonosulfate activator towards monomethylhydrazine degradation: Enhanced electron transfer and 1O2 dominated non-radical pathway

•The recyclable composite of CoFe-LDH with NF for PMS activation.•Complete MMH removal can be achieved with TOC removal efficiency of 80%.•1O2 species and electron transfer pathways were dominant for MMH decomposition.•DFT and XPS analysis elucidated momentous active species of Co and Ni in catalysis.•The sustainability of Co/Fe-LDH/NF was verified in terms of stability, reusability and metal leaching.