One-step synthesis of FeOOH/black phosphorus nano-composite: Synergistic achieving system's excellent oxygen evolution property

In the study, by hydrothermal method, FeOOH nano-materials were grown on the surface of black phosphorus (BP) nanosheets to prepare FeOOH/BP composite. As an oxygen evolution reaction (OER) electrocatalyst, its overpotential was only 191 mV at the current density of 20 mA center dot cm(-2), with a Tafel slope of 49.9 mV center dot dec(-1). After 1 000 cycles, its overpotential only increased by 3 mV, showing the best stability. FeOOH was loaded on the BP surface, which can hinder BP oxidation and enhance its carrier conduction ability. And the loaded nano-FeOOH had a small scale and a weak crystalline nature, which is conducive to enriching their active site and increasing the active area. The synergy of this binary system is the main reason for the OER performance improvement. By comparison, it was found that the active area of FeOOH/BP reached 26.9 mF center dot cm(-2), which was 2.3 times that of pure FeOOH (11.8 mF center dot cm(-2)) and 1.6 times that of pure BP nanosheets (16.8 mF center dot cm(-2)). The excellent activity of this composite material is not only attributed to the morphology change of FeOOH, which significantly expands its effective active area but also benefits from the encapsulated BP, which has better dispersion and stronger conductivity.