| 초록 |
Ni- and Ru-based electrocatalysts with increasing Ni/Ru ratio were designed through a one-step heat treatment at 250ºC of ruthenate nanosheets, and NiCl2.6H2O and NaH2PO2.H2O precursors, under Ar flow. The pristine Ru-electrode underwent a preferential ruthenate-to-metallic Ru phase transformation, resulting in a remarkable HER performance. A favored interaction between Ni ions and the negatively charged ruthenate surface permitted an in-situ growth of Ni2P moieties with size below 5 nm. XPS results showed, however, an unforeseen swift oxidation of Ni2P to NiO and NiOOH species. At a Ni/Ru ratio of 0.35, the emerging oxidized species established a synergetic pathway toward a 1.7-fold OER enhancement. An antagonistic effect in the HER performance of these hybrid materials was, nonetheless, simultaneously observed. Our results reflect the difficulty in the integration of multiple phases during synthesis and the effects of the interaction between nanocomponents. |
