Improving electrocatalytic activities of FeCo2O4@FeCo2S4@PPy electrodes by surface/interface regulation

Constructing bi-functional electrocatalysts with multi-active sites is significant to enhance the catalytic performances. However, it is still a large challenge to obtain high efficient catalysts for full water electrolysis. Herein, we design novel sandwich-like FeCo2O4@FeCo2S4@PPy catalysts through a facile preparation strategy. The as-fabricated samples present an excellent electrocatalytic performance with an overpotential of 98.2 mV for HER at -10 mA cm(-2), 280 mV for OER and a cell voltage of 1.63 V at 50 mA cm(-2). The outstanding performances can be contributed to in-situ electrochemical activation and synergistic effects of electrode materials. It benefits to surface/interface modulation forming active Co and Fe oxyhydroxides in electrochemical reaction process.