Surface Reconstruction of Ni–Fe Layered Double Hydroxide Inducing Chloride Ion Blocking Materials for Outstanding Overall Seawater Splitting

摘要

Generation of hydrogen fuel via electrochemical water splitting powered bysustainable energy, such as wind or solar energy, is an attractive path towardthe future renewable energy landscape. However, current water electrolysisrequires desalinated water resources, eventually leading to energy costs andwater scarcity. The development of cost-effective electrocatalysts capableof splitting saline water feeds directly can be an evident solution. Herein,a surface reconstructed nickel-iron layered double hydroxide (NF-LDH) isreported as an exceptionally active and durable bifunctional electrocatalyst forsaline water splitting without chloride corrosion. The surface reconstructedNF-LDH consists of Ni3Fe alloy phase interconnected in a 2D network inwhich an ultrathin (≈2 nm) and low-crystalline NiFe (oxy)hydroxide phase areformed on the surface. The NiFe (oxy)hydroxide phase draws large anodiccurrent densities, satisfying the level of practical application, while the Ni3Fealloy phase is simultaneously responsible for the high catalytic activity forcathodic reactions and superior corrosion resistance. The surface reconstructedNF-LDH electrode can be easily fabricated in a large electrode area(up to 25 cm~2) and can successfully produce hydrogen fuels from saline waterpowered by the laboratory-made low-intensity photovoltaic cell.