ABSTRACT
Herein, multi-core-shell structure Co/FeC@N-doped hollow carbon (Co/FeC@NHC) with tunable carbon shell thickness is well crafted by a novel and simple strategy. Novel core-shell structure consisting of polydopamine (PDA) shell with different thickness and bimetal-based metal-organic frameworks (MOFs) Co/Fe core with cubic morphology are first prepared, followed by a thermal and etching treatments to fabricate hollow composite materials composed of multiple Co/FeC cores evenly distributed in N-doped carbon shell. PDA acts as a carbon and nitrogen source simultaneously to form N-doped hollow carbon in this procedure. Creatively, the N-doped hollow carbon shell protects Co/FeC core and against the degradation, in addition to enhance the conductivity of Co/FeC@NHC. Through adjusting the PDA shell thickness simply, Co/FeC@NHC with tunable N-doped carbon shell thickness is well crafted. The Co/FeC@NHC-1 with the best electrocatalytic performance is obtained by optimizing the thickness of N-doped hollow carbon shell. The Co/FeC@NHC-1 exhibits the highest activity for the oxygen evolution reaction (OER) and outstanding stability and durability. Hence, this research may establish a promising path for the rational design of metals@carbon composite with controllable structure which can act as highly efficient electrocatalysts for (OER).
ABSTRACT
The high electrocatalytic performance plays a decisive role in the efficient electrochemical sensing of electrocatalysts. A spiral chiral carbon tube (HLCNT) loaded with gold nanoparticles (AuNPs) was prepared by electrochemical methods. Dopamine was first electropolymerized on the surface of the HLCNT, and then it acted as a localizer to uniformly load the AuNPs onto the surface of the HLCNT. The dopamine-localized gold nanoparticles @ left-handed spiral chiral carbon nanotubes (HLCNT-AuNPs-2) material combined the chiral structure of chiral carbon nanotubes and the high conductivity of AuNPs. The HLCNT-AuNPs-2 realized the qualitative and quantitative detection of tyrosine (Tyr) and tryptophan (Trp) isomers by their different oxidation potentials and current signals. Through quantitative detection, the analytical results showed that the detection limit of l-Trp was calculated to be 5.31 µM, and the detection limit of l-Tyr was 9.04 µM. More importantly, the material realized the real sample detection of amino acids, which is of great significance for the practical detection of amino acid isomers in medicine and biology.
