One-Step Synthesis of N-Doped Carbon and Its Application as a Cost-Efficient Catalyst for the Oxygen Reduction Reaction in Microbial Fuel Cells

Article abstract of DOI:10.1002/cplu.201500057

Nitrogen-doped carbon with a high surface area was prepared by the one-step pyrolysis of cellulose paper under NH₃ gas, and has been developed as an alternative to Pt/C for the oxygen reduction reaction in microbial fuel cells (MFCs).The electrochemical tests showed that the catalytic performance of N-doped carbon in neutral media was significantly better than that of undoped carbon, with an onset of 0.21 V. The maximum power density of MFCs with the N-doped carbon catalyst (1041±90 mWm^-2) was much higher than that of Pt/C-based MFC (584±10 mWm^-2), while the cost was significantly lower. These results demonstrated that such N-doped carbon has the advantages of low cost and high efficiency, and can be a promising alternative to Pt/C in large-scale applications of MFCs.

Full text of DOI:10.1002/cplu.201500057

DOI: 10.1002/cplu.201500057
Full Papers
One-Step Synthesis of N-Doped Carbon and Its Application
as a Cost-Efficient Catalyst for the Oxygen Reduction
Reaction in Microbial Fuel Cells
[a]
[b]
[c]
Guizhou Yue,* Kai Meng, and Qin Liu
Nitrogen-doped carbon with a high surface area was prepared
mum power density of MFCs with the N-doped carbon catalyst
ꢀ
2
by the one-step pyrolysis of cellulose paper under NH gas,
(1041ꢁ90 mWm ) was much higher than that of Pt/C-based
3
ꢀ2
and has been developed as an alternative to Pt/C for the
oxygen reduction reaction in microbial fuel cells (MFCs).The
electrochemical tests showed that the catalytic performance of
N-doped carbon in neutral media was significantly better than
that of undoped carbon, with an onset of 0.21 V. The maxi-
MFC (584ꢁ10 mWm ), while the cost was significantly lower.
These results demonstrated that such N-doped carbon has the
advantages of low cost and high efficiency, and can be a prom-
ising alternative to Pt/C in large-scale applications of MFCs.
Introduction
[
9]
As a new green energy technology, microbial fuel cells (MFCs)
Some conducting polymers, such as polyaniline and polypyr-
[1–3]
[10]
have attracted tremendous attention in recent years.
MFCs
role, were also considered. But so far these catalysts have
can be used to generate electricity directly from wastewater,
through microbial metabolism at the anode and reduction of
electron acceptors at the cathode. Oxygen is considered as
a promising electron acceptor due to its ready availability and
still not overcome face the challenges of limited performance
and high cost due to high loading. Promising alternatives are
[11]
carbon-based materials, including activated carbon (AC),
[
12,13]
[14]
granules,
nanotubes,
biochar derived from sewage
[
4]
[15]
low cost. Similar to metal–air batteries and chemical fuel
cells, the development of MFCs has been hindered by the
poor kinetics of the oxygen reduction reaction (ORR), especially
due to the neutral medium which is favorable for the microor-
sludge, due to the advantages of high electrocatalytic activi-
ty, environmental friendliness, and relatively low cost. Despite
great progress in the development of carbon catalysts for the
ORR, finding a better way to further improve the catalytic per-
formance and satisfy the requirements for MFC application is
still highly desirable.
[
5]
ꢀ
ꢀ
ganism. The ORR can proceed via a 4 e or 2 e pathway, de-
pending on catalyst. Platinum (Pt) is usually used as an effi-
ꢀ
cient catalyst in MFCs to facilitate ORR through the 4 e path-
An effective approach can be provided by heteroatom
[15–17]
way. However, the catalyst accounts for the majority of the
MFC cost, and is the bottleneck for the large-scale application
doping on carbon,
in particular nitrogen doping. But only
a few studies about the application of N-doped carbon in
MFCs have been reported so far. N-doped nanotubes, which
were synthesized by chemical vapor deposition (CVD), ob-
[
6]
of MFCs.
Extensive research has been conducted to find a cost-effi-
cient alternative to Pt. Transition metal macrocyclic com-
pounds, such as phthalocyanines and porphyrins, were devel-
[18]
tained comparable power density to Pt/C in MFCs. The re-
searchers also applied N-doped graphene to MFC systems as
[
7]
[19]
oped as cathodic catalysts to replace Pt in MFCs, and subse-
a cathodic catalyst. However, these catalysts were based on
[8]
quently metal complexes and metal oxides were tested.
nanostructured carbon prepared by a complex procedure, and
they are not practical for large-scale application. More atten-
tion has been paid to the choice of inexpensive activated
carbon to improve the performance of cathodes, as it is
among the most promising catalysts in the MFC field. For ex-
ample, an MFC with an N-doped AC catalyst, which is synthe-
sized by pyrolysis of AC in the presence of solid source of ni-
trogen in the presence of solid source of nitrogen, that is, cy-
[a] Dr. G. Yue
College of Basic Sciences
Sichuan Agricultural University
Ya’an, Sichuan 625014 (P. R. China)
Fax: (+86)835-2886189
E-mail: yueguizhou@sicau.edu.cn
[b] K. Meng
[20]
anamide, outperformed the MFC with an Pt/C catalyst. How-
ever, pretreatment of the AC with acidic and alkaline solutions
was required before the pyrolysis, and the improved electroca-
talytic activity was attributed predominantly to the pretreat-
ment rather than the N-doping. The defects introduced by the
pretreatment facilitate N-doping during the subsequent pyroly-
sis of the carbon material in the presence of nitrogen precur-
College of Agricultural Sciences
Sichuan Agricultural University
Chengdu 611130 (P. R. China)
[
c] Q. Liu
Fujian Institute of Research on the Structure of Matter
Chinese Academy of Sciences
YangQiao West Road 155
Fuzhou 350002 (P. R. China)
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sors. Meanwhile, the N-doped activated carbon (AC-N) pre-
ing from 2 to 20 mm. This was further validated in the transmis-
sion electron microscopy (TEM) images (Figure 1C). Scanning
TEM and element mapping images suggest that the nitrogen
is uniformly distributed on the carbon, indicating the N atoms
can be homogeneously doped into the carbon frameworks by
this method (Figure 1E–H). Furthermore, the energy-dispersive
X-ray (EDX) spectra of the as-prepared sample indicate that the
atomic ratios of N and O are about 2.31% and 4.17%, respec-
tively.
pared by pyrolysis of AC under NH gas showed high ORR cat-
3
[
21]
alytic activity in MFCs.
AC can be made from raw lignocellulosic biomass, such as
coconut shells and wood chips. So it is quite possible to form
N-doped carbon based on lignocellulosic biomass by a simpli-
fied process. And most importantly, the oxygen-rich functional
groups in lignocellulosic biomass are considered to be favora-
ble for N-doping, which is quite different from the N-doping of
[
22]
pure carbon. Cellulose is one of the most abundant, sustain-
able, and oxygen-rich materials in nature. Herein, cellulose
XPS was performed to study the element content and its
state of bonding with carbon framework. In synthesized N-
doped carbon, the atomic ratios of N and O were 2.48% and
4.23%, respectively (Figure 2A), which is agree with the EDX
result. The XPS spectrum (Figure 2B) has an apparent N1s
peak, which can be split into three peaks corresponding to
pyridinic-N (398.3 eV), pyrrolic-N (400.1 eV), and graphitic-N
paper was heated with NH gas to prepare N-doped carbon.
3
The catalytic activity of N-doped carbon for the ORR in neutral
medium was examined by electrochemical measurements. Fi-
nally, the performance of the N-doped carbon catalyst in MFCs
was evaluated and compared with that of Pt/C in MFCs.
(
401.2 eV), strongly suggesting the successful incorporation of
nitrogen atoms into carbon framework. Furthermore, the pyri-
dinic-N and graphitic-N dominated in the N-doped carbon,
both of which have positive effects on electrochemical per-
Results and Discussion
Characterization of the catalyst
[25,26]
formance of carbon catalyst.
The N-doped carbon catalyst was synthesized through the py-
N2 adsorption–desorption analysis was also performed to
study the pore structure of the carbon catalyst (Figure 3A).
rolysis of cellulose paper in the presence of NH gas. X-ray dif-
3
2
ꢀ1
fraction (XRD) analysis was used to investigate the effect of N-
doping on the structure of the carbon catalyst. As shown in
Figure 1A, two diffraction peaks at 2q=258 and 438, corre-
sponding to the graphitic (002) and (101) planes, were ob-
served in the XRD pattern. The shaper diffraction peaks at 2q=
The BET surface area of the N-doped carbon is 1294.9 m g ,
which is much higher than that of undoped carbon
2
ꢀ1
(786.9 m g ). Both doped and undoped carbon exhibit typical
type I adsorption–desorption isotherms with a steep increase
at low relative pressure (P/P <0.1), implying the characteristics
0
2
58 for the N-doped carbon indicate a higher graphitization
of uniform microporosity. From the pore size distributions
(PSD) plots, a sharp peak at about 2 nm was observed for N-
doped carbon, while a broad peak over the mesopore range
was observed for undoped carbon (Figure 3B). After N-doping,
the micropore area increased
degree than that in the undoped carbon. As shown in Fig-
ure 1B,D, after the pyrolysis at 9508C, the fiber-like morpholo-
gy of the catalyst still remained, with the fiber diameter rang-
2
ꢀ1
from
668.7 m g
ꢀ1
to
2
1170.6 m g , accounting for
major of the BET area. The in-
creased micropores might due
to the reaction between carbon
atoms and NH during the pyrol-
3
ysis of cellulose paper. These
abundant, dominant, and uni-
form micropores might provide
additional active sites for ORR,
thereby promoting the catalytic
[23]
activity. These results demon-
strate that the N atoms doped in
carbon changed the carbon sur-
face properties slightly and the
higher surface area plays a key
role in improving the ORR cata-
lytic activity.
Electrochemical Performance
The electrocatalytic activity of N-
doped carbon was first evaluat-
ed by cyclic voltammetry (CV)
Figure 1. A) XRD patterns of N-doped and undoped carbon. SEM (B), TEM (C), high-resolution SEM (D), and STEM
(E) images of the N-doped carbon. F–H) Elemental mappings of the rectangle area in (E).
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Figure 3. A) N
2
sorption isotherms and B) pore size distributions of N-doped
and undoped carbon.
Figure 2. A) XPS survey and B) high-resolution N1s spectrum of the N-doped
carbon.
measurements in 50 mm phosphate-buffered saline (PBS), and
compared to the performance of commercial Pt/C (20 wt%).
As shown in Figure 4A, N-doped
create favorable positive charged sites for O adsorption, thus
2
[23]
promoting ORR activity.
carbon exhibited an obvious
peak in O -saturated solution,
2
whereas no peak appeared
when it was measured in N -sa-
2
turated solution, confirming the
electrocatalytic activity of N-
doped carbon for the ORR. The
N-doped
carbon
displayed
a
peak potential of ꢀ0.11 V,
which was more negative than
that of commercial Pt/C (0.07 V).
Subsequently, linear sweep vol-
tammetry (LSV) measurements
were performed to further inves-
tigate the electrocatalytic activi-
ties of the catalyst on a rotating
disk electrode (RDE) at 1600 rpm
in O -saturated solution. It can
2
be observed from Figure 4B that
the onset potential of N-doped
carbon was 0.21 V, which was
not as excellent as that of Pt/C
(0.32 V), but was greatly im-
proved compared over that of
the undoped carbon (ꢀ0.27 V).
N-doping could break the elec-
Figure 4. A) CV of N-doped and undoped carbon in O
2 2
-saturated (solid line) and N -saturated (dotted line) 50 mm
PBS. B) LSVs for different catalysts in O -saturated PBS at a rotation rate of 1600 rpm. C) LSVs for N-doped carbon
2
troneutrality of carbon and at different rotation rates. D) K–L plots for different catalysts at ꢀ0.50 V.
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The current density of N-doped carbon increased with the
rotation rates (from 400 to 2400 rpm), as presented in Fig-
ure 4C. The Koutecky–Levich (K–L) plots at a potential of
ꢀ
0.5 V were obtained and displayed good linearity. The n
value for N-doped carbon carbonate at ꢀ0.5 V was calculated
ꢀ
ꢀ
to be 2.95, indicating a combined 2 e /4 e pathway for the N-
doped catalyst. Whereas the n value for Pt/C was 3.74, which is
higher than that for N-doped carbon. These results are in
agreement with the CV results.
It is worth noting that the conditions of the RDE tests where
diffusion limitation can be ignored due to aeration are quite
different from the conditions in air-cathode MFCs. Besides, the
loading of the N-doped carbon catalyst was almost 8 times
ꢀ
2
higher than that of Pt/C (0.5 mgcm ) in the fabricated air-
cathode, comparing to the constant loading in RDE test. Thus
the catalytic performance of the catalyst reflected in RDE is
likely not significant enough to predict the performance in
a real air-cathode MFC.
Electricity Generation in MFCs
The voltage of MFCs at 1000 W became stable and repeatable
after about one week. The cell voltage of about 530 mV ach-
ieved by N-doped carbon which was higher than that of Pt/C
(
490 mV), whereas the undoped carbon without NH treatment
3
only achieved a voltage of 420 mV. Moreover, no voltage
decay occurred for N-doped carbon after more than 9 cycles,
indicating very good durability—an important factor for the
long-term operation of MFCs (Figure 5). Polarization and
power density curves were examined to further evaluate the
performances of different catalysts. As shown in Figure 6A,
a highest open circuit voltage was achieved by Pt/C, but its
polarization was more serious than N-doped carbon. And
a maximum power density of 1041ꢁ90 mWmꢀ was generat-
ed by N-doped carbon, which was higher than that of undop-
Figure 6. A) Polarization curves and power density curves, and B) electrode
potentials curves of MFCs with different catalysts.
sponsible for the improved power density of the MFC, since all
anode potential curves were almost constant whereas the
cathode potential varied with the catalyst (Figure 6B).These re-
sults demonstrated that N-doping could be an effective way to
improve the ORR catalytic activity of carbon.
2
ꢀ
2
ꢀ2
ed carbon (420 mWm ) and Pt/C (584ꢁ10 mWm ) and
agreed well with the cell voltage output results. According to
the electrode potential curves, the cathodic catalyst was re-
As mentioned previously, the performance of catalyst in real
MFCs is quite different from that in RDE tests, due to the limit-
ing diffusion of oxygen. Many factors, such as binder types, dif-
fusion layers, and fabrication methods, affect the air-cathode
performance in MFCs. In this study, the air-cathode with the N-
doped carbon catalyst was fabricated by the rolling method
with polytetrafluoroethylene (PTFE) binder, while the air-cath-
ode with Pt/C was fabricated by the brushing method with
Nafion binder considering the scarcity of Pt. The rolling
method can be a promising method to produce low-cost,
[27]
high-performance, and scalable air-cathodes. In addition, the
N-doped carbon catalyst was synthesized by heating cellulosic
materials in NH gas, with the advantage of low cost, renewa-
3
bility, and easy scale-up.
Conclusion
In this study, N-doped carbon was synthesized successfully by
direct pyrolysis of cellulose paper under NH and possesses
3
2
ꢀ1
Figure 5. Voltage output curves of MFCs with different catalysts.
a large surface area up to 1294.9 m g . The electrochemical
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tests revealed that the N-doped carbon exhibits high electroca-
talytic activity toward the oxygen reduction reaction under
neutral conditions. The application of N-doped carbon in air-
cathode MFCs as a catalyst was examined. A maximum power
density of 1041ꢁ90 mWmꢀ was achieved with N-doped
carbon, higher than that achieved with commercial Pt/C (584ꢁ
Electrochemical analysis
Electrochemical measurements were conducted at room tempera-
ture in a typical three-electrode system equipped with a platinum
wire as the counter electrode and an Ag/Ag Cl electrode (saturated
with KCl, 0.197 V vs. SHE) as the reference electrode. All potentials
in this study were measured versus the Ag/AgCl reference elec-
trode. To prepare the working electrode, 10 mg of each catalyst
was first ultrasonically dispersed in 2 mL of 0.5 wt% Nafion solu-
tion. Then 4 mL of catalyst ink was pipetted onto the glassy carbon
2
ꢀ
2
1
0 mWm ). Both the nitrogen dopant and the large surface
areas were considered to play a key role in the improved per-
formance. The preparation of this N-doped carbon is cost-effi-
cient and easily to be scaled-up, and therefore this catalyst is
promising for application in MFCs.
(
0
GC) electrode (5 mm diameter), leading to a catalyst loading of
.10 mgcm . Finally the electrode was dried at room temperature
ꢀ2
before measurement.
In the electrochemical measurements a 50 mm phosphate-buffered
ꢀ
1
solution (PBS, pH 7.0) solution containing 10.9233 gL
ꢀ
1
ꢀ1
Na HPO ·12H O, 3.042 gL NaH PO ·2H O, and 0.31 gL NH Cl,
.13 gL KCl was used as the electrolyte. The cyclic voltammetry
2
4
ꢀ
2
2
4
2
4
Experimental Section
1
0
Materials
(CV) tests were run first in N
-saturated solution, and then trans-
2
ferred to O -saturated solution which were then saturated with N ,
2
2
A 3 g sample of cellulose paper from tissue (Fuzhou, Fujian, China)
was placed into a quartz tube furnace. The furnace was heated to
in the potential range from ꢀ0.6 V to 0.6 V at a scan rate of
ꢀ1
0
.05 Vs . The solutions were saturated with N and O by bub-
2
2
ꢀ1
9
8
508C at a rate of 7.58Cmin under NH gas with a flow rate of
3
[21,22]
bling nitrogen and oxygen gas for 0.5 h, respectively. The liner
sweep voltammetry (LSV) experiments using a rotating disk elec-
0 sccm, and maintained at the target temperature for 1 h.
After cooling down to room temperature, the black products were
washed with abundant amounts of distilled water and dried in
a vacuum drying oven overnight. For comparison, undoped carbon
was also prepared by pyrolysis of cellulose paper under Ar gas
under the same conditions.
trode (RDE) were performed with the O -saturated electrolyte at
a scan rate of 0.005 Vs and at various rotation rates from 400 to
2
ꢀ1
2
400 rpm. O2 was continuously streamed into the headspace of
the electrolyte during the LSV test.
The electron transfer numbers (n) were calculated from the slopes
of the Koutecky–Levich (K–L) plots using Equations (1) and (2).
À
Á
ꢀ
1
¼ ðJLÞꢀ1þðJkÞꢀ1¼ Bw ꢀ1þðJkÞꢀ1
1=2
Air-cathode fabrication
J
ð1Þ
ð2Þ
The air-cathode consisted of stainless-steel mesh (SSM) with a gas
diffusion layer (GDL) on the air-facing side and a catalyst layer (CL)
on the water-facing side. The GDLs of all air-cathodes in this
study were the same and made by rolling carbon black (ECP-
2
=3 ꢀ1=6
B ¼ 0:62nFC ðD Þ
v
0
0
[23]
where J is the measured current; w is the electrode rotation rate in
ꢀ1
ꢀ1
rads ; F is the Faraday constant (96485 Cmol ); C is the concen-
6
00JD, Cuike Chemical Co. Ltd., Shanghai, China) and polytetrafluo-
0
ꢀ6
ꢀ3)
tration of O (1.26ꢁ10 molcm ; D is the diffusion coefficient of
roethylene (PTFE) emulsion (60 wt%, Dupont, USA) with the mass
ratio of 3:7 into the SSM (mesh 40ꢁ40, type 304) to form a film
2
0
ꢀ
5
2
ꢀ1
O (2.7ꢁ10 cm s ), and n is the kinematic viscosity of the elec-
2
2
ꢀ1
trolyte (0.01 cm s ).
(
0.3 mm thickness), followed by sintering at 3408C for 25 min. The
carbon catalyst was ground evenly, and then mixed with PTFE
binder with a mass ratio of 6:1. The mixture was roll-pressed to
form a film of 0.2 mm thickness, and finally rolled onto the other
side of the SSM to obtain the final air-cathode of 0.5 mm thickness.
For comparison, the Pt-based air-cathode was prepared by brush-
ing commercial Pt/C (20 wt%, Heson, China) onto the water-facing
side of the SSM using 0.5 wt% Nafion solution as the binder, and
MFC construction and test
Single-chamber MFC reactors with total volume of 28 mL were
constructed to measure the performances of the catalyst as previ-
[4]
ously described. Three air-cathodes based on different catalysts
including N-doped carbon, undoped carbon, commercial Pt were
tested. Anodes were graphite fiber brushes (2.5 cm outer diameter
and 2.5 cm long, Jilin Chemical Fiber Group Co., Ltd., China) which
were soaked in acetone overnight and heated at 4508C for 30 min
before inoculation with microorganisms. MFC reactors were inocu-
lated with wastewater from a local wastewater treatment plant
and fed with a medium contained (per liter of 50 mm PBS): acetate
ꢀ2
the Pt loading was 0.5 mgcm .
Characterization
The morphology of the N-doped carbon was observed by scanning
electron microscopy (SEM, JEOL-6700F). Transmission electron mi-
croscope (TEM) images were obtained by a JEM-2010 instrument
at an acceleration voltage of 200 kV. The elements on the surface
of the N-doped carbon were identified by X-ray photoelectron
spectroscopy (XPS, VG ESCALAB 250) with an Al Ka source at
(1 g), vitamin solution (5 mL), and trace element solution (12.5 mL).
The medium was replaced when the voltage decreased below
5
1
0 mV. Unless otherwise noted, the external resistor was fixed at
000 W. All MFCs were operated in duplicate at 308C.
1
487 eV. XPSPEAK software was used for the peak fitting analysis.
Voltage output of MFC was monitored at 1 min intervals using
a date acquisition system (LANHE, CT2001A, Wuhan, China). Polari-
zation curves and power density curves were obtained by measur-
ing the voltage generated at various external resistors from
1000 W to 30 W, with each resistor used for one complete cycle.
The electrode potentials were measured by adding an Ag/AgCl ref-
X-ray diffraction (XRD) was performed on a MiniFlex II diffractome-
ter with Cu Ka radiation (l=1.54 ꢂ).The specific surface areas were
measured through N adsorption at 77 K using ASAP 2010 and cal-
culated by the Brunauer–Emmett–Teller (BET) equation. The PSD
plots were acquired based on the density function theory model.
2
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erence electrode. Current density and power density were calculat-
ed as previously described and normalized to the projected area of
the air-cathode (7 cm ).
[13] S. Freguia, K. Rabaey, Z. Yuan, J. Keller, Electrochim. Acta 2007, 53, 598–
6
03.
[14] Y. Yuan, T. Yuan, D. Wang, J. Tang, S. Zhou, Bioresour. Technol. 2013, 144,
15–120.
2
[24]
1
[
[
15] K. Gong, F. Du, Z. Xia, M. Durstock, L. Dai, Science 2009, 323, 760–764.
16] Z. W. Liu, F. Peng, H. J. Wang, H. Yu, W. X. Zheng, J. Yang, Angew. Chem.
Acknowledgements
2
011, 123, 3315–3319.
[
17] Z. Yang, Z. Yao, G. Li, G. Fang, H. Nie, Z. Liu, X. Zhou, X. a. Chen, S.
This study was supported by the Science & Technology Depart-
ment of Sichuan Province (2012JY0118) and Sichuan Agricultural
University.
Huang, ACS Nano 2011, 6, 205–211.
[18] L. Feng, Y. Yan, Y. Chen, L. Wang, Energy Environ. Sci. 2011, 4, 1892–
899.
1
[
[
19] L. Feng, Y. Chen, L. Chen, ACS Nano 2011, 5, 9611–9618.
20] B. Zhang, Z. Wen, S. Ci, S. Mao, J. Chen, Z. He, ACS Appl. Mater. Interfa-
ces 2014, 6, 7464–7470.
21] T. Xing, Y. Zheng, L. H. Li, B. C. C. Cowie, D. Gunzelmann, S. Z. Qiao, S.
Huang, Y. Chen, ACS Nano 2014, 8, 6856–6862.
22] W. Luo, B. Wang, C. G. Heron, M. J. Allen, J. Morre, C. S. Maier, W. F. Stick-
le, X. Ji, Nano Lett. 2014, 14, 2225–2229.
23] H. Dong, H. Yu, X. Wang, Environ. Sci. Technol. 2012, 46, 13009–13015.
24] B. E. Logan, B. Hamelers, R. Rozendal, U. Schrçder, J. Keller, S. Freguia, P.
Aelterman, W. Verstraete, K. Rabaey, Environ. Sci. Technol. 2006, 40,
Keywords: cellulose · microbial fuel cells · N-doped carbon ·
oxygen reduction reaction
[
[
[
[
[
[
[
1] B. E. Logan, J. M. Regan, Environ. Sci. Technol. 2006, 40, 5172–5180.
2] B. E. Logan, K. Rabaey, Science 2012, 337, 686–690.
3] K. Rabaey, W. Verstraete, Trends Biotechnol. 2005, 23, 291–298.
4] H. Liu, B. E. Logan, Environ. Sci. Technol. 2004, 38, 4040–4046.
5] F. Zhao, F. Harnisch, U. Schrçder, F. Scholz, P. Bogdanoff, I. Herrmann, En-
viron. Sci. Technol. 2006, 40, 5193–5199.
[
[
5
181–5192.
25] Y. Zhao, K. Watanabe, K. Hashimoto, J. Am. Chem. Soc. 2012, 134,
9528–19531.
26] X. Yang, W. Zou, Y. Su, Y. Zhu, H. Jiang, J. Shen, C. Li, J. Power Sources
014, 266, 36–42.
27] H. Dong, H. Yu, X. Wang, Q. Zhou, J. Feng, Water Res. 2012, 46, 5777–
787.
[
[
[
[
[
[
[
6] E. HaoYu, S. Cheng, K. Scott, B. Logan, J. Power Sources 2007, 171, 275–
1
281.
7] F. Zhao, F. Harnisch, U. Schrçder, F. Scholz, P. Bogdanoff, I. Herrmann,
Electrochem. Commun. 2005, 7, 1405–1410.
8] M. Lu, S. Kharkwal, H. Y. Ng, S. F. Y. Li, Biosens. Bioelectron. 2011, 26,
2
5
4728–4732.
9] Y. Yuan, J. Ahmed, S. Kim, J. Power Sources 2011, 196, 1103–1106.
[
[
10] Y. Yuan, S. Zhou, L. Zhuang, J. Power Sources 2010, 195, 3490–3493.
11] F. Zhang, S. Cheng, D. Pant, G. V. Bogaert, B. E. Logan, Electrochem.
Commun. 2009, 11, 2177–2179.
Received: February 8, 2015
Revised: March 11, 2015
[12] B. Erable, N. Duteanu, S. M. S. Kumar, Y. Feng, M. M. Ghangrekar, K.
Scott, Electrochem. Commun. 2009, 11, 1547–1549.
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FULL PAPERS
Heating cellulose under an ammonia
atmosphere results in an N-doped
carbon material with high surface area
that exhibits high electrocatalytic activi-
ty for the oxygen reduction reaction in
microbial fuel cells (MFCs). This N-
doped carbon is an inexpensive, highly
efficient catalyst, and can be a promising
alternative to Pt/C in large-scale applica-
tions of MFCs.
G. Yue,* K. Meng, Q. Liu
& – &&
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One-Step Synthesis of N-Doped
Carbon and Its Application as a Cost-
Efficient Catalyst for the Oxygen
Reduction Reaction in Microbial Fuel
Cells
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