| Autor: |
Hu, Songhan, Wang, Kai, Xu, Xinxin, Wang, Qiang |
| Předmět: |
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| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; 11/28/2024, Vol. 53, p17819-17828, 10p |
| Abstrakt: |
Although Ni-based materials are widely used as electrocatalysts, it remains necessary to further explore their selectivity towards the four- or two-electron oxygen reduction reaction (ORR). Herein, it is proposed to synthesize NiO@NCNTs (NCNTs = N-doped carbon nanotubes) using a metal–organic framework (MOF), [Ni(BZIDA)(H2O)]n (NiMOF, BZIDA = benzimidazole-5,6-dicarboxylic acid), as a precursor after calcination with dicyandiamide (DCDA). Regarding NiO@NCNTs, small NiO particles are distributed in NCNTs derived from DCDA homogeneously. NiO@NCNTs act as a typical two-electron electrocatalyst. The H2O2 production rate of NiO@NCNTs reaches 0.5 mol g−1 h−1 at 0.46 V (vs. RHE). After the doping of Co2+ in NiMOF, Co/NiO@NCNTs were synthesized using a similar method, with the four-electron character shown in ORR. A Zn–air battery was assembled by applying Co/NiO@NCNTs as the cathode material. When discharge occurs at 5 and 10 mA cm−2, its specific capacitance reaches 779.3 and 832.2 mA h g−1 with an energy density of 928.6 and 948.5 W h kg−1, respectively. Theoretical calculations suggest a variation in ORR selectivity between NiO@NCNTs and Co/NiO@NCNTs, which results from their different interactions with OOH*. This study demonstrates the effect of the structure on ORR selectivity for Ni-based electrocatalysts. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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