Defect-promoted nanoparticles−nanorod Ni−NiMoO4 heterogeneous nanostructures as efficient electrocatalysts to overall water/urea splitting in fresh/sea water

The heterogeneous nanoparticles−nanorod Ni−NiMoO 4   nanostructures grown   in situ   on nickel foam (Ni−NiMoO 4 /NF) were rationally engineered as efficient electrocatalysts. The morphological and compositional   features cooperatively propel high-performance electrocatalysis to hydrogen evolution reaction (η 10 , η 100 , and η 200   values are 26/84/113 mV in fresh water and 27/101/132 mV in seawater), urea oxidation reaction (η 10 , η 100 , and η 200   values are 1.321/1.340/1.356 and 1.329/1.344/1.361 V in fresh/seawater). The Ni−NiMoO 4 /NF nanostructures therefore perform a low cell voltage of 1.506/1.509@10 mA cm −2   in fresh/sea water. Specifically, the record cell voltage even drops to as low as 1.339/1.361 V in fresh/sea water for   overall urea splitting (OUS) reaction with   a long-term stability for 240 h@100 mA cm −2   toward OUS in seawater. More importantly, to realize a green manner, we also evaluated a solar-driven H 2   production. Even in seawater, H 2   gas was collected in high speed under solar illumination on a commercial solar panel.