Limits...
Gelatin-derived sustainable carbon-based functional materials for energy conversion and storage with controllability of structure and component.

Wang ZL, Xu D, Zhong HX, Wang J, Meng FL, Zhang XB - Sci Adv (2015)

Bottom Line: The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts.The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-N x /C (D1 + D3) species.The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.

ABSTRACT
Nonprecious carbon catalysts and electrodes are vital components in energy conversion and storage systems. Despite recent progress, controllable synthesis of carbon functional materials is still a great challenge. We report a novel strategy to prepare simultaneously Fe-N-C catalysts and Fe3O4/N-doped carbon hybrids based on the sol-gel chemistry of gelatin and iron with controllability of structure and component. The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts. The active sites of FeN4/C (D1) and N-FeN2+2/C (D3) are identified by Mössbauer spectroscopy, and most of the Fe ions are converted into D1 or D3 species. The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-N x /C (D1 + D3) species. As an anode material for lithium storage, Fe3O4/carbon hybrids exhibit superior rate capability and excellent cycling performance. The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.

No MeSH data available.


Illustration of the preparation procedure of IAG-C catalysts and Fe3O4@AGC electrode materials.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4644076&req=5

Figure 1: Illustration of the preparation procedure of IAG-C catalysts and Fe3O4@AGC electrode materials.

Mentions: The overall synthetic procedure for the Fe-N-C catalyst is presented in Fig. 1 and in fig. S1. The precursor solution is first prepared by dissolving gelatin, iron nitrate, and ammonium nitrate (fig. S1A). The obvious interaction between iron cation and gelatin is demonstrated by UV-visible spectroscopy (fig. S2). During the thermal treatment at 80°C for 24 hours, the solvent of water gradually evaporates, and complexed iron ions gradually hydrolyze into amorphous ferric hydroxide, accompanying the decomposition of nitrate ions and a big volume expansion as shown in fig. S1B. The mass of final gel is found to equal the total mass of gelatin, ferric hydroxide, and ammonium nitrate, which indicates that ammonium nitrate does not change during the sol-gel process and that it uniformly dispersed in the composite gel with the evaporation of water (fig. S3). In the comparable experiments, it is found that the introduction of iron nitrate in the gelatin solution is the crucial premise for the sol-gel process owing to the interaction between metal ions and gelatin (figs. S4 to S6). After high-temperature treatment, the homogeneous composite gel is converted into Fe-N-C catalyst with homogeneous distribution of nitrogen, iron, and carbon. A large amount of micropores and mesopores are produced during the decomposition of ammonium nitrate, leading to a high surface area of Fe-N-C catalyst (fig. S7).


Gelatin-derived sustainable carbon-based functional materials for energy conversion and storage with controllability of structure and component.

Wang ZL, Xu D, Zhong HX, Wang J, Meng FL, Zhang XB - Sci Adv (2015)

Illustration of the preparation procedure of IAG-C catalysts and Fe3O4@AGC electrode materials.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644076&req=5

Figure 1: Illustration of the preparation procedure of IAG-C catalysts and Fe3O4@AGC electrode materials.
Mentions: The overall synthetic procedure for the Fe-N-C catalyst is presented in Fig. 1 and in fig. S1. The precursor solution is first prepared by dissolving gelatin, iron nitrate, and ammonium nitrate (fig. S1A). The obvious interaction between iron cation and gelatin is demonstrated by UV-visible spectroscopy (fig. S2). During the thermal treatment at 80°C for 24 hours, the solvent of water gradually evaporates, and complexed iron ions gradually hydrolyze into amorphous ferric hydroxide, accompanying the decomposition of nitrate ions and a big volume expansion as shown in fig. S1B. The mass of final gel is found to equal the total mass of gelatin, ferric hydroxide, and ammonium nitrate, which indicates that ammonium nitrate does not change during the sol-gel process and that it uniformly dispersed in the composite gel with the evaporation of water (fig. S3). In the comparable experiments, it is found that the introduction of iron nitrate in the gelatin solution is the crucial premise for the sol-gel process owing to the interaction between metal ions and gelatin (figs. S4 to S6). After high-temperature treatment, the homogeneous composite gel is converted into Fe-N-C catalyst with homogeneous distribution of nitrogen, iron, and carbon. A large amount of micropores and mesopores are produced during the decomposition of ammonium nitrate, leading to a high surface area of Fe-N-C catalyst (fig. S7).

Bottom Line: The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts.The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-N x /C (D1 + D3) species.The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.

ABSTRACT
Nonprecious carbon catalysts and electrodes are vital components in energy conversion and storage systems. Despite recent progress, controllable synthesis of carbon functional materials is still a great challenge. We report a novel strategy to prepare simultaneously Fe-N-C catalysts and Fe3O4/N-doped carbon hybrids based on the sol-gel chemistry of gelatin and iron with controllability of structure and component. The catalysts demonstrate higher catalytic activity and better durability for oxygen reduction than precious Pt/C catalysts. The active sites of FeN4/C (D1) and N-FeN2+2/C (D3) are identified by Mössbauer spectroscopy, and most of the Fe ions are converted into D1 or D3 species. The oxygen reduction reaction (ORR) activity correlates well with the surface area, porosity, and the content of active Fe-N x /C (D1 + D3) species. As an anode material for lithium storage, Fe3O4/carbon hybrids exhibit superior rate capability and excellent cycling performance. The synthetic approach and the proposed mechanism open new avenues for the development of sustainable carbon-based functional materials.

No MeSH data available.