Plasma-induced exfoliation in NiMn-layered double hydroxides for enhanced oxygen evolution reaction activity

As one of typical two-dimensional nanomaterials, layered double hydroxides (LDHs) exhibited unique properties in oxygen evolution reaction (OER). In this work, NiMn-LDHs were successfully exfoliated to nanosheets by cold plasma treatment. The exfoliation mechanism was proposed, that is, high energy electrons produced by plasma excited the intercalated water in host layers to generate H · , HO · and H + . The intermediate combined with CO 3 2- to produce CO 2 gas, which induced gas expansion to achieve the exfoliation of NiMn-LDHs. A large number of oxygen vacancies on LDHs nanosheets were also generated in the process of exfoliation. The increased active sites improved the intrinsic activity in OER. After plasma treatment was conducted for 30 min, the NiMn-LDHs exhibited high OER performance with an overpotential of 357 mV to achieve a current density of 10 mA cm –2 and a Tafel slope of 60.1 mV dec –1 in alkaline conditions.