RESUMEN
Urea electrooxidation with favorable thermodynamic potential is highly anticipated but suffering from sluggish kinetics. Deciphering the activity origin and achieving rational structure design are pivotal for developing highly efficient electrocatalyst for urea oxidation reaction (UOR). Herein, nitrogen penetrated nickel nanoparticles confined in carbon nanotubes (Ni-NCNT) is successfully achieved to drive UOR. Active origin of Ni-NCNT is decoded to be the in-situ generated Ni2+δO(OH)ads according to comprehensive analysis. The electrophilic Ni2+δ and protophilic OHads could targeted capture O and H atoms from urea, respectively, achieving molecule activation and accelerating the subsequent proton coupled electron transfer reactions. Nitrogen penetration is identified to promote prior formation of Ni2+δO(OH)ads and push up the d band center of Ni-NCNT, enhancing urea adsorption and subsequent molecule cleavage reactions. As a result, Ni-NCNT exhibits superior UOR performance. This work supplies valuable insights for the rational design and construction of efficient nickel-based catalyst for driving UOR.
RESUMEN
Sb holds the promise of being a high performance anode for sodium ion batteries(SIBs), while effective preparation of decent antimony(Sb) based anode materials for sodium storage is still under exploration. Herein, we propose a simple approach to achieve a high performance anode, using polyaniline as the carbon source and SbCl3as the metal source. Synergetic polymerization and hydrolysis reactions combined with subsequent thermal reduction endow Sb/C-PANI electrode possessing ultrafine Sb nanoparticles symmetrically distributed in the nitrogen(N) doped porous carbon matrix. The Sb/C-PANI electrode exhibits excellent sodium storage performance, featured for a high reversible capacity of 469.5 mAh g-1after 100 cycles at 100 mA g-1and 336.5 mAh g-1after 300 cycles under 500 mA g-1. Such impressive performance will advance the development of Sb based anode materials for sodium storage. The present approach provides a compatible strategy for preparation of anode materials with high reversible capacity and long lifespan.