RESUMEN
In situ exsolved nanoparticles (NPs) on surfaces perform well in many catalytic applications. Herein, an emerging technique of pulsed electric current (PEC) for facilitating NPs exsolution was firstly utilized in functional materials towards tailoring structure and morphology of materials. PEC facilitated Ni NPs exsolution in situ and the exposed active sites were highly dispersed on the LaCrO3 substrate surface. Such result was confirmed by combining x-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. As a consequence, PEC-treated and untreated LaCrO3 perovskite samples were employed as electrocatalysts for oxygen evolution reaction (OER). The PEC-treated samples exhibit obviously improved OER activity (lower overpotential, smaller Tafel slope) and lower reaction resistance than the untreated samples. This illustrates that the exsolved Ni NPs driven by PEC are beneficial for the OER performance and are probably the components of the OER active sites.