Amorphous Iron Boride in Situ Grown on Black Phosphorus Sheets: A Promising Electrocatalyst for OER

The development of electrochemical oxygen evolution reaction (OER) catalysts with a simple preparation method and high catalytic efficiency is a primary step to improve energy conversion efficiency. In this work, a series of samples, including black phosphorus (BP) sheets, iron Bolide (Fe 2 B), Fe 2+ doped BP (Fe 2+ /BP) sheets, and iron Bolide/black phosphorus (Fe 2 B/BP) sheets were prepared, and their electrochemical properties were investigated. It was found that the composite of amorphous Fe 2 B/BP sheets showed the best OER performance, which was significantly superior to BP sheets, Fe 2 B, and Fe 2+ /BP sheets. It could be seen that Fe 2 B/BP sheets composite had only a low overpotential of 179 mV at the current density of 10 mA/cm 2 in 1 M KOH, and its Tafel slope was 70 mV/dec. In particular, after 1000 cycles, its overpotential only rose by 11 mV at the same current density of 10 mA/cm 2 , while, after 10 h, its current density only decreased by 0.91 mA/cm 2 at the overpotential of 179 mV, showing good stability. This study will mainly explore the performance improvement mechanism in an attempt to synthesize better catalysts for OER.