Electron-rich NiFe layered double hydroxides via interface engineering for boosting electrocatalytic oxygen evolution

Modulating the local electronic structures of the active sites represents a promising strategy to improve the activity of electrocatalysts. Here, a facile interface engineering strategy is reported to fabricate electron-rich NiFe layer double hydroxide (LDH) by interfacing with conductive polyaniline (PANI) for significantly improving the OER activity. Experimental and theoretical investigations unveil that the unique electron-rich states of active metal sites in NiFe LDH via the strong interfacial coupling effect can optimize the adsorption free energy of reactive oxygenated intermediates. Remarkably, the electron-rich NiFe LDH electrocatalysts exhibit outstanding OER performance with a low overpotential of 220 mV at a current density of 10 mA cm−2, a small Tafel slope of 44 mV dec−1, and good stability.