Enhancing oxygen and hydrogen evolution activities of perovskite oxide LaCoO effective doping of platinum.

In this study, a series of perovskite oxides LaCo Pt O ( = 0, 0.02, 0.04, 0.06, and 0.08) were prepared by the citric acid-ethylenediaminetetraacetic acid (CA-EDTA) complexing sol-gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Then, the samples were investigated as OER and HER bifunctional electrocatalysts in alkaline media. Compared with other catalysts, LaCoPtO had good stability and presented more activity at a lower overpotential of 454 mV (at 10 mA cm), a lower Tafel slope value of 86 mV dec and a higher mass activity of 44.4 A g for OER; it displayed a lower overpotential of 294 mV (at -10 mA cm), a lower Tafel slope value of 148 mV dec and a higher mass activity of -34.5 A g for HER. The improved performance might depend on a larger ECSA, faster charge transfer rate and higher ratio of the highly oxidative oxygen species (O /O). Furthermore, the e orbital filling of Co approaching 1.2 in the B site might play a leading role.