Thermal-induced surface defective Co/Fe–Co planar hybrid composite nanosheet with enhanced catalytic activity in the Fenton-like reaction

Surface defective or heterojunction sites of catalysts generally afford remarkable catalytic activity thanks to their high-surface-energy. Regularly-generating multiple defective sites on the surface of a catalyst is exceedingly promising in many reactions. In this study, we report an unexpected Co/Fe–Co planar hybrid composite nanosheet with serried surface defects including surface biphasic junction sites or defective holes. A facile thermal-induced process was applied to trigger the generation of defective sites on planar Co/Fe–Co hydroxides. Through a controlled thermal process, massive serried CoO nanocrystals were in situ dissolved out of the surface of cobalt hydroxide, while defective surface holes were formed on the Fe-doped Co(OH)2 nanosheets under a prolonged thermal procedure. The morphology and microscale structure of the resulting Co/Fe–Co hybrid 2-dimensional (2D) composites were systematically examined by virtue of various characterization techniques. As expected, the obtained surface defective Co/Fe–Co planar composites showed obviously enhanced catalytic activity in the Fenton-like reaction. Based on a catalytic study, we proved that the CoO nanocrystals densely-distributed on thinlayer Co(OH)2. Uniformly-introduced Fe heteroatoms in the inter-structure of Co(OH)2, along with the formed surface defective holes on Fe–Co hybrid composites, are synergistically responsible for increased catalytic removal efficiency of MB in the presence of peroxomonosulfate.