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Efficient and durable hydrogen evolution electrocatalyst based on nonmetallic nitrogen doped hexagonal carbon.

Liu Y, Yu H, Quan X, Chen S, Zhao H, Zhang Y - Sci Rep (2014)

Bottom Line: Herein, a highly active and stable nonmetallic electrocatalyst, nitrogen doped hexagonal carbon (NHC), was developed for hydrogen production.It exhibited high activity for hydrogen evolution with a low overpotential of only 65 mV, an apparent exchange current density of 5.7 × 10(-2) mA cm(-2) and a high hydrogen production rate of 20.8 mL cm(-2) h(-1) at -0.35 V.The superior hydrogen evolution activity of NHC stemmed from the intrinsic electrocatalytic property of hexagonal nanodiamond, the rapid charge transfer and abundance of electrocatalytic sites after nitrogen doping.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.

ABSTRACT
The feasibility of renewable energy technology, hydrogen production by water electrolysis, depends on the design of efficient and durable electrocatalyst composed of earth-abundant elements. Herein, a highly active and stable nonmetallic electrocatalyst, nitrogen doped hexagonal carbon (NHC), was developed for hydrogen production. It exhibited high activity for hydrogen evolution with a low overpotential of only 65 mV, an apparent exchange current density of 5.7 × 10(-2) mA cm(-2) and a high hydrogen production rate of 20.8 mL cm(-2) h(-1) at -0.35 V. The superior hydrogen evolution activity of NHC stemmed from the intrinsic electrocatalytic property of hexagonal nanodiamond, the rapid charge transfer and abundance of electrocatalytic sites after nitrogen doping. Moreover, NHC was stable in a corrosive acidic solution during electrolysis under high current density.

No MeSH data available.


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Stability of NHC electrode for HER.(a) Time dependence of electrocatalytic current density during electrolysis at overpotential 0.27 V for NHC electrode. (b) Polarization curves of NHC electrode before and after potential sweeps (-0.4 ~ 0.6 V, 100 mV s−1) for 10,000 cycles in 0.5 M H2SO4.
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f5: Stability of NHC electrode for HER.(a) Time dependence of electrocatalytic current density during electrolysis at overpotential 0.27 V for NHC electrode. (b) Polarization curves of NHC electrode before and after potential sweeps (-0.4 ~ 0.6 V, 100 mV s−1) for 10,000 cycles in 0.5 M H2SO4.

Mentions: A promising material for electrocatalytic HER should exhibit not only high activity but also good durability. The long-term stability of NHC electrode was examined by electrolysis at high current density in 0.5 M H2SO4. As shown in Figure 5a, although NHC electrode is operated in a corrosive acidic solution at overpotential 0.27 V, its cathodic current density remains around 30.4 mA cm−2 for 30 h operation. After 10,000 cycles of potential sweeps at -0.4 ~ 0.6 V, NHC electrode retains a polarization curve similar to the initial one with negligible loss of cathodic current density (Figure 5b). These results demonstrate that NHC electrode is durable during electrocatalytic hydrogen production. Its stability compares well with those of other newly reported noble-metal free electrocatalysts193233, while NHC electrode is still in the series displaying the best performance so far. The excellent durability of NHC electrode arises from the superior electrochemical stability and corrosion resistance of nanodiamond.


Efficient and durable hydrogen evolution electrocatalyst based on nonmetallic nitrogen doped hexagonal carbon.

Liu Y, Yu H, Quan X, Chen S, Zhao H, Zhang Y - Sci Rep (2014)

Stability of NHC electrode for HER.(a) Time dependence of electrocatalytic current density during electrolysis at overpotential 0.27 V for NHC electrode. (b) Polarization curves of NHC electrode before and after potential sweeps (-0.4 ~ 0.6 V, 100 mV s−1) for 10,000 cycles in 0.5 M H2SO4.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4213799&req=5

f5: Stability of NHC electrode for HER.(a) Time dependence of electrocatalytic current density during electrolysis at overpotential 0.27 V for NHC electrode. (b) Polarization curves of NHC electrode before and after potential sweeps (-0.4 ~ 0.6 V, 100 mV s−1) for 10,000 cycles in 0.5 M H2SO4.
Mentions: A promising material for electrocatalytic HER should exhibit not only high activity but also good durability. The long-term stability of NHC electrode was examined by electrolysis at high current density in 0.5 M H2SO4. As shown in Figure 5a, although NHC electrode is operated in a corrosive acidic solution at overpotential 0.27 V, its cathodic current density remains around 30.4 mA cm−2 for 30 h operation. After 10,000 cycles of potential sweeps at -0.4 ~ 0.6 V, NHC electrode retains a polarization curve similar to the initial one with negligible loss of cathodic current density (Figure 5b). These results demonstrate that NHC electrode is durable during electrocatalytic hydrogen production. Its stability compares well with those of other newly reported noble-metal free electrocatalysts193233, while NHC electrode is still in the series displaying the best performance so far. The excellent durability of NHC electrode arises from the superior electrochemical stability and corrosion resistance of nanodiamond.

Bottom Line: Herein, a highly active and stable nonmetallic electrocatalyst, nitrogen doped hexagonal carbon (NHC), was developed for hydrogen production.It exhibited high activity for hydrogen evolution with a low overpotential of only 65 mV, an apparent exchange current density of 5.7 × 10(-2) mA cm(-2) and a high hydrogen production rate of 20.8 mL cm(-2) h(-1) at -0.35 V.The superior hydrogen evolution activity of NHC stemmed from the intrinsic electrocatalytic property of hexagonal nanodiamond, the rapid charge transfer and abundance of electrocatalytic sites after nitrogen doping.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.

ABSTRACT
The feasibility of renewable energy technology, hydrogen production by water electrolysis, depends on the design of efficient and durable electrocatalyst composed of earth-abundant elements. Herein, a highly active and stable nonmetallic electrocatalyst, nitrogen doped hexagonal carbon (NHC), was developed for hydrogen production. It exhibited high activity for hydrogen evolution with a low overpotential of only 65 mV, an apparent exchange current density of 5.7 × 10(-2) mA cm(-2) and a high hydrogen production rate of 20.8 mL cm(-2) h(-1) at -0.35 V. The superior hydrogen evolution activity of NHC stemmed from the intrinsic electrocatalytic property of hexagonal nanodiamond, the rapid charge transfer and abundance of electrocatalytic sites after nitrogen doping. Moreover, NHC was stable in a corrosive acidic solution during electrolysis under high current density.

No MeSH data available.


Related in: MedlinePlus