RESUMO
Developing high-efficiency electrocatalysts for nitrate-to-ammonia transformation holds significant promise for the production of ammonia, a crucial component in agricultural fertilizers and as a carbon-free energy carrier. In this study, we propose a viable strategy involving sulfur doping to modulate both the microstructure and electronic properties of CoSe2 for nitrate reduction. This approach remarkably enhances the conversion of nitrate to ammonia by effectively regulating the adsorption capability of nitrogenous intermediates. Specifically, sulfur-doped CoSe2 nanowires (S-CoSe2 NWs) exhibit a peak faradaic efficiency of 93.1% at -0.6 V vs. RHE and achieve the highest NH3 yield rate of 11.6 mg h-1 cm-2. Mechanistic investigations reveal that sulfur doping facilitates the creation of highly charged active sites, which enhance the adsorption of nitrite and subsequent hydrogenation, leading to improved selectivity towards ammonia production.
RESUMO
A significant challenge in direct seawater electrolysis is the rapid deactivation of the cathode due to the large scaling of Mg(OH)2. Herein, we synthesized a Pt-coated highly disordered NiCu alloy (Pt-NiCu alloy) electrode with superior solidophobic behavior, enabling stable hydrogen generation (100 mA cm-2, >1000 h durability) and simultaneous production of Mg(OH)2 (>99.0% purity) in electrolyte enriched with Mg2+ and Ca2+. The unconventional solidophobic property primarily stems from the high surface energy of the NiCu alloy substrate, which facilitates the adsorption of surface water and thereby compels the bulk formation of Mg(OH)2 via homogeneous nucleation. The discovery of this solidophobic electrode will revolutionarily simplify the existing techniques for seawater electrolysis and increase the economic viability for seawater electrolysis.