Integrating Cr doped FeOOH into FeSe2 nanoparticles for efficient water oxidation at large current densities

Developing a non-noble metal-based oxygen evolution electrocatalyst that works under high current densities is a challenging task in hydrogen production by water splitting. Herein, an efficient OER electrocatalyst was formed by combining Cr-doped FeOOH with high OER activity and FeSe 2 with high conductivity. Through the addition of FeSe 2 and the incorporation of Cr ion, the conductivity and intrinsic activity of the obtained Cr-FeOOH/FeSe 2 /NF towards OER are dramatically enhanced. To specific, the required overpotential is only 242 mV to realize the current density of 100 mA/cm 2 . In addition, the Cr-FeOOH/FeSe 2 /NF can output large current densities at industrial level, which only needs the overpotential of 293 and 336 mV to deliver the current density of 500 and 1000 mA/cm 2 , respectively. In addition, the overpotential is as low as 291 mV to attain 1000 mA/cm 2 in 30 wt% KOH solution. More importantly, the obtained Cr-FeOOH/FeSe 2 /NF electrode can stable work for 80 h at such a high current density of industrial level, and the overpotential does not increase significantly. This result suggests that the obtained electrocatalyst has latent capacity for industrial application. This work points out the direction for building high-performance oxygen evolution electrocatalysts at large current densities.