Ultrathin NiMn-LDH nanosheet structured electrocatalyst for enhanced electrocatalytic urea oxidation

Water electrolysis has been widely considered as a promising technique for generating hydrogen. However, oxygen evolution reaction (OER) as a sluggish anodic reaction, usually suffers from high overpotential, which greatly impedes the efficiency of hydrogen generation. Herein, we report an ultrathin NiMn-LDH/CFC growth on commercial carbon fiber cloth (U-NiMn-LDH/CFC) substrate through a facile hydrothermal method. The U-NiMn-LDH/CFC can be successfully used to assemble an energy-saving water splitting system via integrating anodic urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). The as-prepared U-NiMn-LDH/CFC nanosheets with ultrathin structure exhibit reliable electrocatalytic activities toward UOR (1.351 V vs. RHE@20 mA cm −2 ) and HER (169 mV@10 mA cm −2 ). A two-electrode water splitting cell is further constructed and delivers almost 210 mV lower oxidation potential at 10 mA cm −2 with containing (1.0 M KOH) 0.5 M urea in comparison to that in pure overall water splitting. Furthermore, the above two-electrode system shows excellent electrolysis stability.