M13 Virus-Incorporated Biotemplates on Electrode ... - ACS Publications

Subscriber access provided by GRIFFITH UNIVERSITY

Article

M13 Virus-Incorporated Biotemplates on Electrode Surfaces to Nucleate Metal Nanostructures by Electrodeposition Shanmugam Manivannan, Inhak Kang, Yeji Seo, Hyo-Eon Jin, Seung-Wuk Lee, and Kyuwon Kim ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b06545 • Publication Date (Web): 05 Sep 2017 Downloaded from http://pubs.acs.org on September 5, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

M13 Virus-Incorporated Biotemplates on Electrode Surfaces to Nucleate Metal Nanostructures by Electrodeposition Shanmugam Manivannan[a], Inhak Kang[a],, Yeji Seo[a] , Hyo-Eon Jin[b,c], Seung-Wuk Lee[b] and Kyuwon Kim[a],* [a]

Electrochemistry Laboratory for Sensors & Energy (ELSE) Department of Chemistry, Incheon National University Incheon 406-772, Republic of Korea. [b] Department of Bioengineering, University of California, Berkeley, California 94720, USA [c] Present address: College of Pharmacy, Ajou University, Suwon 16499, Republic of Korea *E-mail: [email protected]

Abstract: We report a virus-incorporated biological template (biotemplate) on electrode surfaces and its use in electrochemical nucleation of metal nanocomposites as an electrocatalytic material for energy applications. The biotemplate was developed with M13 virus (M13) incorporated in silicate sol–gel matrix as a scaffold to nucleate Au–Pt alloy nanostructures by electrodeposition, together with reduced graphene oxide (rGO). The phage when engineered with Y3E peptides could nucleate Au–Pt alloy nanostructures, which ensured adequate packing density, simultaneous stabilization of rGO, and a significantly increased electrochemically active surface area. Investigation of the electrocatalytic activity of the resulting sol-gel composite catalyst toward methanol oxidation in an alkaline medium showed that this catalyst had greater mass activity than did the biotemplate containing wild-type M13, and than did monometallic Pt and other Au–Pt nanostructures with different compositions and supports. M13 in the nanocomposite materials provided a close contact between the Au–Pt alloy nanostructures and rGO. In addition, it facilitated the availability of an OH– -rich environment to the catalyst. As a result, efficient electron transfer and a synergistic catalytic effect of the Au and Pt in the alloy nanostructures toward methanol oxidation were observed. Our nanocomposite synthesis on the novel biotemplate and its application might be useful for developing novel clean and green energy-generating and energy-storage materials.

Keywords: Biotemplate, Electrodeposition, M13 virus, Au–Pt alloy, Methanol oxidation

1|Page ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

1.

Introduction Developing clean and green renewable energy sources is one of the most critical needs for

mankind. Direct methanol fuel cells (DMFCs) have attracted wide attention as power sources for portable electronic devices and fuel cell vehicles owing to their quick start-up, compactness and light weight, high power density, and simplicity.1-2 Moreover, DMFCs operating in alkaline media show advantageous features such as improved reaction kinetics, and a less corrosive environment for catalysts. DMFCs in alkaline media can also operate at relatively low potentials.2-5 However, wide application of the DMFC still requires addressing multiple issues including its high cost, low durability of its platinum (Pt) catalyst, and the relatively easy passage of methanol through membranes.5-7 In order to decrease the amount of Pt that needs to be loaded into DMFCs and to increase their efficiency levels, a secondary metal such as gold (Au),2 ruthenium (Ru),8-9 copper (Cu),10 and palladium (Pd)11 has been introduced. Pt-based bimetallic (alloy and core–shell) catalysts have been explored to develop DMFCs that operate in alkaline media, and represent an alternative way to minimize the amount of pure Pt-based catalyst loaded.2, 12-13 Furthermore, considerable efforts have been devoted to employing Au–Pt alloy nanostructures in order to take advantage of the synergistic effect between Au and Pt that had already been detemined.14-15 Reduced graphene oxide (rGO) is, due to its unique electronic and chemical properties arising from its 2D structure,16 a promising support for loaded metallic nanostructures in fuel cell applications2, 17-22, it is crucial to prevent its individual sheets from aggregating. In this regard, several approaches have been used to prevent aggregation between individual rGO sheets using biomolecules such as DNA,23 proteins24 and genetically modified viruses.25-27 And the resulting biomolecule-rGO composites have found significant applications in various biosensors28-30 and energy devices.31-32 In addition, substantial research is being pursued to develop rGO as support materials for metal nanostructures.12-13, 18 Such a combination can provide a highly active surface area, enhanced catalytic activity, and durability for long times. In this regard, there is a great need to develop a synthesis of composites of Au–Pt alloy

2|Page ACS Paragon Plus Environment

Page 2 of 32

Page 3 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


nanostructures with low-density packing and suitable solid supports to ensure both the performance and durability of DMFCs. With the recent advent of virus-based bionanotechnology, various viruses have been utilized as biological templates (biotemplates) to synthesize functional nanomaterials. Functional nanostructures resulting from virus-based synthesis have attracted a lot of attention as novel nanoscale platforms due to their advantageous characteristics including their monodispersity, multiple valences, tunable structural features, biocompatibility, stability, and low-cost production.3133

The M13 virus (M13) is particularly interesting here. This virus, which infects bacterial host cells,

is 880 nm in length and 6.6 nm in diameter, consists of a single-stranded DNA enclosed by 2700 identical copies of major coat protein pVIII and capped with five copies of four different minor coat proteins (pIX, pVII, pVI and pIII) at the ends,34 and is stable in a wide range of pH, temperature and organic solvent conditions. Moreover, M13 is considered not harmful in humans and animals. Hence, it has been applied to various biomedical applications such as drug and gene delivery as well as tissue engineering.35-36 In addition, the virus can be engineered to have specific affinity toward selected metal precursors by having certain of its genes modified, with inserted DNA sequences.37-40 Recently, the Belcher group and other research groups have made significant contributions towards the synthesis of various nanostructures based on engineered M13 for various applications including semiconductor synthesis, energy storage, electric generators, and tissue engineering materials.31-32, 4144

The resulting M13 engineered with specific peptides allows them to bind and organize the

precursors, and nucleate metallic nanostructures as biotemplates. Biomineralization of metal nanostructures using peptides expressed on the virus surfaces has proven to be efficient and highly cost effective. On the one hand, biomineralization carried out using M13 by typical chemical deposition could lead to a lack of electrical pathways in electrochemical applications such as DMFCs. On the other hand, biomineralization through electrodeposition could secure electrical pathways by connecting the nanostructures on M13. Therefore, M13 viruses with nanostructures electrodeposited 3|Page ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

on their surfaces might provide excellent biotemplates to synthesize DMFC materials with engineered catalysts. To the best of our knowledge, electrodeposition-based biomineralization on viruses-modified surfaces has never been reported. Here, we report a novel fabrication of a virus-templated silicate sol–gel matrix (SSG) with an rGO dispersion to nucleate Au–Pt alloy nanostructures by electrodeposition. We demonstrated the use of the nanostructures as efficient electrocatalysts of the methanol oxidation reaction (MOR) for DMFC applications. The density of the nanostructures at the electrode surface was controlled with the incorporated viruses and its genetically modified peptide surfaces, which offered a convenient way to synthesize relatively less densely packed metal nanostructures on the biotemplates. We demonstrated the density and shape of the alloy nanostructures that affected the MOR performance to be highly influenced by the peptide sequences on the major coat protein of the virus. Interestingly, the incorporated viruses in the biotemplate did not change the electronic conductivity of the template with rGO and the alloy nanostructures. In addition, the M13 viruses infusion improved the colloidal stability of the rGO and contributed to the generation of an OH–-rich environment for an efficient MOR. 2.

Experimental Section

2.1.

Materials and Methods Graphite (powder 500s (% s–1)

(3),

where (dI/dt)t>500s is the slope of the linear portion of current decay and I0 is the current at the start of polarization back-extrapolated from the linear current decay. The poisoning rates were calculated to be 0.0212 and 0.0075% s–1 for the commercial Pt/C and SSG/M13Y3E/rGO/(Au58.9– Pt41.1) catalysts, respectively. The result further revealed the better poisoning tolerance of the SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalyst. To determine the stability of the SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalyst, 100 continuous cycles of the MOR were carried out using this catalyst (Figures 10C and D). After the 100 cycles, the peak current decreased by only 10.2 %, which indicated that the proposed SSG/M13Y3E/rGO/(Au58.9– Pt41.1) catalyst showed good sensitivity and stability toward the MOR. The durability of the catalyst has been recognized as one of the most important issues to be addressed before commercializing DMFCs. Thus the durability of the SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalyst was further evaluated in

16 | P a g e ACS Paragon Plus Environment

Page 16 of 32

Page 17 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


an accelerated durability test (ADT) by applying linear potential sweeps between 0.6 and 1.1 V at 100 mV/s in 0.5 M H2SO4 electrolyte at room temperature. For comparison, SSG/M13Y3E/rGO/Pt and SSG/M13Wild/rGO/(Au57.7–Pt42.3) catalysts were also studied under the same conditions. Figures S13A(a–f), B(a–f) and C(a–f) show the CVs of the SSG/M13Y3E/rGO/Pt, SSG/M13Wild/rGO/(Au57.7– Pt42.3), and SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalysts, respectively, at initial conditions and then every 250 ADT cycles up to the 1250th ADT cycle. After 250 cycles, the current densities in the hydrogen adsorption/desorption potential regions (–0.2 to 0 V) dropped dramatically with additional CV cycles for all three catalysts. ECSAs were generally observed to decrease with more CV cycles, predominantly during the first 500-750 cycles (Figure S13D). Specifically, after 250, 500, 750, 1000 and 1250 ADT cycles, the ECSAs of SSG/M13Y3E/rGO/Pt, SSG/M13Wild/rGO/(Au57.7–Pt42.3) and SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalysts decreased by 5.6, 10.8 and 12.7%, 58.1, 53.4 and 85.2%, 62.6, 55.9 and 81.3%, 65.3, 60.0 and 78.5%, and 67.5, 61.0 and 76.4%, respectively. Note that the ECSAs did not decrease significantly after 750 cycles. The overall ECSA loss for the three catalysts was on average about 68% after 1250 ADT cycles. Interestingly, the ECSA of the SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalyst (Figure S13C) increased a little bit after 500 cycles, suggesting that new Pt surface features were generated at that point during the cycling test. Pt nanostructures in all three catalysts would have been expected to grow and aggregate during the durability tests owing to Ostwald ripening2, 7, 65 causing the aggregation, coalescence and ECSA loss. Despite our method being very simple, easy to follow, and very convenient for fabricating nanostructures, the performances we obtained were comparable or superior to the previous results obtained from more complicated approaches. Moreover, the use of peptides expressed on the virus surfaces as a surfactant to fabricate metal nanostructures is highly cost effective not only because M13 is a kind of bacteriophage that enables low-cost mass production but also because the corresponding synthetic peptides that give similar effects to those we found for the fabrication are extremely expensive.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

4.

Conclusions In summary, we have demonstrated the preparation of an engineered M13 virus-incorporated

biotemplate on electrode surfaces and its use in the electrodeposition of highly efficient Au–Pt alloy nanostructures for the MOR. The alloy nanostructures on the biotemplate incorporating specifically M13Y3E exhibited significantly higher electrocatalytic activity than did the monometallic counterparts or those incorporating M13Wild or M134E. The SSG/M13Y3E/rGO/(Au58.9–Pt41.1) catalyst showed a larger ECSA and better MOR performance than did the commercial Pt/C catalyst, which we attributed to the improved dispersion of Au-Pt alloy nanostructures on the biotemplate that ensured fast mass transport during the reactions. But in terms of durability, present catalyst suffered after 800 s when compared to commercial Pt/C catalyst. The combination of the biotemplate and electrodeposition could offer a convenient way to control the density of the nanostructures at the electrode surface by allowing for the peptide functionalities and the incorporated virus concentration to be selected, which are essential for optimizing the electrocatalytic performances. The use of peptides expressed on the virus surfaces as a surfactant to fabricate metal nanostructures is highly cost-effective because corresponding synthetic peptides being able to give similar effects to the fabrication are extremely expensive. This simple approach can be extended to other metals and matrices and the fabricated templates should provide highly promising scaffolds for sensors and energy applications including batteries, supercapacitors, and fuel cells.

Associated Content Supporting Information SEM, SEM-EDX and XPS analysis of different modified electrodes; controlled experiments for MOR; comparison of ECSA and mass activities; comparison of different composition effect of Au-Pt nanostructures toward MOR; MOR at different scan rate study; electrochemical durability studies.


Page 18 of 32

Page 19 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Author Information Corresponding Author *E-mail: [email protected] Notes The authors declare no competing financial interest. Acknowledgements This work was partially supported by the Incheon National University (International Cooperative) Research Grant in 2012.

Figures

Figure 1. (a) Schematic illustration of M13wild, M13Y3E and M134E. (b) Schematic representation of SSG/M13Y3E/rGO/(Au–Pt) catalyst fabrication.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 2. (A to C1) SEM images of (A, A1) ITO/SSG/M13Y3E/rGO/Au, (B, B1) ITO/SSG/M13Y3E/rGO/Pt and (C, C1) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes at different magnifications. (D) EDX analysis of ITO/SSG/M13Y3E/rGO/(Au–Pt) electrode.

Figure 3. SEM images of (A) ITO/SSG/M13Y3E/rGO/(Au–Pt), (B) ITO/SSG/M13Wild/rGO/(Au–Pt) and (C) ITO/SSG/M134E/rGO/(Au–Pt) electrodes.


Page 20 of 32

*

*

*

*

*

*

*

*

50

60

(200)

(111)

* *

c

(200)

(111)

* * * *

b

a 10

20

30

40

(311)#

*

(311)

(002)

(220)#φ

*

(220)

d (002)

(111)#φ

(220)

ITO *# Au φ Pt

Intensity (a.u)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(200)#φ

Page 21 of 32

70

80

2 θ (Degree) Figure 4. XRD patterns of (a) ITO/SSG/M13Y3E/rGO, (b) ITO/SSG/M13Y3E/rGO/Au, (c) ITO/SSG/M13Y3E/rGO/Pt and (d) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes.



A

d

Mass activity (A/mg Pt)

2.0 1.5

Ι (mA)

e 1.0

b c

0.5

a

0.0 -0.5 -200

0

200 400

600 800 1000 1200

1.5

e

B

d b

1.0

0.5

c a 0.0 -1000 -800 -600 -400 -200

E vs. Ag/AgCl (mV)



350 300 250 200

e

150 100

d

50

c a

0 0

b 300

600

900

0

200 400 600

E vs. Ag/AgCl (mV)

C

400

1200

1500

1.5

b

D

1.0

0.5

a

0.0

-1000 -800 -600 -400 -200

0

200 400 600

E vs. Ag/AgCl (mV)

Time / Sec

Figure 5. CVs of (a) ITO/(Au–Pt), (b) ITO/SSG/(Au–Pt), (c) ITO/SSG/M13Y3E/(Au–Pt), (d) ITO/SSG/rGO/(Au–Pt) and (e) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes in (A) 0.5 M H2SO4 and in (B) 0.1 M CH3OH and 0.1 M KOH at a scan rate of 50 mV/s. (C) Amperometric i–t curves observed for A(a–e) in 0.1 M CH3OH and 0.1 M KOH at an applied potential of –0.3 V. (D) comparison of ITO/SSG/M13Y3E/rGO/(Au–Pt) electrode in the (a) absence and (b) presence of 0.1 M CH3OH in 0.1 M KOH at a scan rate of 50 mV/s.

1.5

c

0.5

a

0.0 -0.5 -1.0 -200

0

200

400

600

800

E vs. Ag/AgCl (mV)

1000 1200

1.5

B

1.0

0.5

0.0

b a

-1000 -800 -600 -400 -200

C

400

c

0


b


A 1.0

Ι (mA)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 32

200 400 600

E vs. Ag/AgCl (mV)

350 300 250 200 150

b

100

a

50 0 0

300

600

900

1200

Time / Sec

Figure 6. (A, B) CVs of (a) ITO/SSG/M13Y3E/rGO/Au, (b) ITO/SSG/M13Y3E/rGO/Pt and (c) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes in (A) 0.5 M H2SO4 and in (C) 0.1 M CH3OH and 0.1 M


1500

Page 23 of 32

KOH at a scan rate of 50 mV/s. (C) Amperometric i–t curves observed for A(b,c) electrodes in 0.1 M CH3OH and 0.1 M KOH at an applied potential of –0.3 V.

A

Ι (mA)

1.0


1.5

c b a

0.5

0.0

-0.5 -200

0

200 400 600 800 1000 1200

1.5

B

c

1.0

b a

0.5

0.0 -1000 -800 -600 -400 -200

0

200 400 600

E vs. Ag/AgCl (mV)

E vs. Ag/AgCl (mV)

Figure 7. CVs obtained at (a) ITO/SSG/M13Wild/rGO/(Au–Pt), (b) ITO/SSG/M134E/rGO/(Au–Pt) and (c) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes in (A) 0.5 M H2SO4 and in (B) 0.1 M CH3OH and

0.0

40 0

ECSA

ECSA/gPt

1.5 1.0 0.5 0.0

SSG/M13-Y3E/rGO/(Au–Pt)

2.0

SSG/M13-W/rGO/(Au–Pt) SSG/M13-4E/rGO/(Au–Pt)

80

2.5

ITO/(Au–Pt) SSG/(Au–Pt) SSG/M13-Y3E/(Au–Pt) SSG/rGO/(Au–Pt)

0.5

120

3.0

SSG/M13-Y3E/rGO/Pt SSG/M13-Y3E/rGO/Au

1.0

160

Peak Current (A/mg Pt)

1.5

200

SSG/M13-Y3E/rGO/(Au–Pt)

2.0

240

C 3.5 SSG/M13-W/rGO/(Au–Pt) SSG/M13-4E/rGO/(Au–Pt)

2.5

SSG/M13-Y3E/rGO/Pt SSG/M13-Y3E/rGO/Au ITO/(Au–Pt) SSG/(Au–Pt) SSG/M13-Y3E/(Au–Pt) SSG/rGO/(Au–Pt)

2

3.0

280

2

3.5

B 320 Area (m /g Pt)

A 4.0

SSG/M13-Y3E/rGO/Pt SSG/M13-Y3E/rGO/Au ITO/(Au–Pt) SSG/(Au–Pt) SSG/M13-Y3E/(Au–Pt) SSG/rGO/(Au–Pt) SSG/M13-Y3E/rGO/(Au–Pt) SSG/M13-W/rGO/(Au–Pt) SSG/M13-4E/rGO/(Au–Pt)

0.1 M KOH at the scan rate of 50 mV/s.

Area (cm )

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Mass Activity

Figure 8. (A) ECSAs, (B) ECSAs per Pt gram and (C) mass activities mono- and bimetallic catalysts.



Figure 9. Schematic representation of MOR at ITO/SSG/M13Y3E/rGO/(Au–Pt) electrode.

1.5

b

A



400

1.0

0.5

a 0.0

B 300

200

b 100

a 0

-1000 -800 -600 -400 -200

0

0

200 400 600

2.0

600

900

1200

1500

2.0

C

Cycle 1

1.5

1.5

j (A)

1.0

300

Time / Sec

E vs. Ag/AgCl (mV)


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 32

Cycle 100

0.5

D

1.0

0.5

0.0 -1000 -800 -600 -400 -200

0.0 0

200 400 600

E vs. Ag/AgCl (mV)

0

10 20 30 40 50 60 70 80 90 100

[Cycle Number]

Figure 10. (A) CVs of (a) ITO/Pt/C and (b) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes in (A) 0.1 M CH3OH and 0.1 M KOH at a scan rate of 50 mV/s. (B) Amperometric i–t curves observed for (a) ITO/Pt/C and (b) ITO/SSG/M13Y3E/rGO/(Au–Pt) electrodes in 0.1 M CH3OH and 0.1 M KOH at an applied potential of –0.3 V. (C) CVs obtained at ITO/SSG/M13Y3E/rGO/(Au–Pt) electrode in 0.1 M CH3OH and 0.1 M KOH at the scan rate of 50 mV/s with 1 to 100 cycles. (D) Corresponding calibration plot.


Page 25 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 1. Electrochemical Parameters of MOR Derived from Various Modified Electrodes. Specific modified electrodes

ECSA

ECSA

onset

anodic

mass activity

2

(m /g

potential

peak

(A/mg Pt)

Pt)

(V)

potential

2

mass

(cm )

(mg 2

Pt/cm

)

If/Ib

(V)

ITO/(Au62.5–Pt37.5)

0.00532

1.18

22.19

–0.590

–0.010

0.1278

10.10

ITO/SSG/(Au63.3–Pt36.7)

0.00437

1.36

31.06

–0.570

0.238

0.9798

14.94

ITO/SSG/M13Y3E/(Au62.3–Pt37.7)

0.00463

1.38

29.93

–0.574

0.038

0.2760

11.13

ITO/SSG/rGO/(Au60.3–Pt39.7)

0.00322

1.31

40.81

–0.644

0.296

1.3093

10.66

ITO/SSG/M13Y3E/rGO/(Au64–

0.00210

0.36

17.2

–0.345

0.003

0.1336

5.59

0.00107

1.63

153.23

–0.642

–0.082

1.5428

10.37

0.00090

0.44

48.89

–0.525

0.021

1.0470

6.04

0.00269

1.22

45.53

–0.516

0.061

0.6840

-

0.00230

1.08

47.20

–0.479

–0.102

0.7790

-

ITO/SSG/M13Y3E/rGO/Au100

0.01333

0.25

1.88

-

-

-

-

ITO/SSG/M13Y3E/rGO/Pt100

0.01006

2.14

21.30

–0.570

0.152

0.4060

3.81

Commercial Pt/C

0.0051

-

-

–0.563

–0.563

0.2389

8.07

Pt36) ITO/SSG/M13Y3E/rGO/(Au58.9– Pt41.1) ITO/SSG/M13Y3E/rGO/(Au57.7– Pt42.3) ITO/SSG/M13wild/rGO/(Au57.7– Pt42.3) ITO/SSG/M134E/rGO/(Au61.1– Pt38.9)

References: 1.

Huang, T.; Mao, S.; Zhou, G.; Zhang, Z.; Wen, Z.; Huang, X.; Ci, S.; Chen, J., A High-

Performance Catalyst Support for Methanol Oxidation with Graphene and Vanadium Carbonitride.

Nanoscale 2015, 7 (4), 1301–1307. 2.

Gnanaprakasam, P.; Jeena, S. E.; Selvaraju, T., Hierarchical Electroless Pt Deposition at Au

Decorated Reduced Graphene Oxide via a Galvanic Exchanged Process: An Electrocatalytic Nanocomposite with Enhanced Mass Activity for Methanol and Ethanol Oxidation. J. Mater. Chem.

A 2015, 3 (35), 18010–18018.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

3.

Cherevko, S.; Kulyk, N.; Chung, C. H., Utilization of Surface Active Sites on Gold in

Preparation of Highly Reactive Interfaces for Alcohols Electrooxidation in Alkaline Media.

Electrochim. Acta 2012, 69, 190–196. 4.

Wang, J.; Shi, R.; Guo, X.; Xi, J.; Zhao, J.; Song, C.; Wang, L.; Zhang, J., Highly Active Pt-

on-Au Catalysts for Methanol Oxidation in Alkaline Media Involving a Synergistic Interaction between Pt and Au. Electrochim. Acta 2014, 123, 309–316. 5.

Zhao, Y.; Yang, X.; Tian, J.; Wang, F.; Zhan, L., Methanol Electro-Oxidation on Ni@Pd

Core-Shell Nanoparticles Supported on Multi-Walled Carbon Nanotubes in Alkaline Media. Int. J.

Hydrogen Energy 2010, 35 (8), 3249–3257. 6.

Gurau, B.; Smotkin, E. S., Methanol Crossover in Direct Methanol Fuel Cells: A Link

between Power and Energy Density. J. Power Sources 2002, 112 (2), 339–352. 7.

Kristian, N.; Wang, X., Ptshell-Aucore/C Electrocatalyst with a Controlled Shell Thickness

and Improved Pt Utilization for Fuel Cell Reactions. Electrochem. Commun. 2008, 10 (1), 12–15. 8.

Franceschini, E. A.; Bruno, M. M.; Williams, F. J.; Viva, F. A.; Corti, H. R., High-Activity

Mesoporous Pt/Ru Catalysts for Methanol Oxidation. ACS Appl. Mater. Interfaces 2013, 5 (21), 10437–10444. 9.

Lu, S.; Eid, K.; Ge, D.; Guo, J.; Wang, L.; Wang, H.; Gu, H., One-Pot Synthesis of PtRu

Nanodendrites as Efficient Catalysts for Methanol Oxidation Reaction. Nanoscale 2017, 9(3), 1033– 1039. 10.

Eid, K.; Wang, H.; He, P.; Wang, K.; Ahamad, T.; Alshehri, S. M.; Yamauchi, Y.; Wang, L.,

One-Step Synthesis of Porous Bimetallic PtCu Nanocrystals with High Electrocatalytic Activity for Methanol Oxidation Reaction. Nanoscale 2015, 7 (40), 16860–16866. 11.

Zhu, C.; Guo, S.; Dong, S., PdM (M = Pt, Au) Bimetallic Alloy Nanowires with Enhanced

Electrocatalytic Activity for Electro-Oxidation of Small Molecules. Adv. Mater. 2012, 24 (17), 2326–2331. 12.

Guo, X.; Guo, D. J.; Qiu, X. P.; Chen, L. Q.; Zhu, W. T., A Simple One-Step Preparation of

High Utilization AuPt Nanoparticles Supported on MWCNTs For Methanol Oxidation in Alkaline Medium. Electrochem. Commun. 2008, 10 (11), 1748–1751. 13.

Xu, Y.; Dong, Y.; Shi, J.; Xu, M.; Zhang, Z.; Yang, X., Au@Pt Core-Shell Nanoparticles

Supported on Multiwalled Carbon Nanotubes for Methanol Oxidation. Catal. Commun. 2011, 13 (1), 54–58. 14.

Mott, D.; Luo, J.; Njoki, P. N.; Lin, Y.; Wang, L.; Zhong, C. J., Synergistic Activity of Gold-

Platinum Alloy Nanoparticle Catalysts. Catal. Today 2007, 122 (3–4), 378–385.


Page 26 of 32

Page 27 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


15.

Yang, L.; Yang, W.; Cai, Q., Well-Dispersed PtAu Nanoparticles Loaded into Anodic Titania

Nanotubes: A High Antipoison and Stable Catalyst System for Methanol Oxidation in Alkaline Media. J. Phys. Chem. C 2007, 111 (44), 16613–16617. 16.

Guo, C. X.; Guai, G. H.; Li, C. M., Graphene Based Materials: Enhancing Solar Energy

Harvesting. Adv. Energy Mater. 2011, 1 (3), 448–452. 17.

Guo, S.; Dong, S.; Wang, E., Three-Dimensional Pt-on-Pd Bimetallic Nanodendrites

Supported on Graphene Nanosheet: Facile Synthesis and used as an Advanced Nanoelectrocatalyst for Methanol Oxidation. ACS Nano 2010, 4 (1), 547–555. 18.

Lv, J. J.; Li, S. S.; Zheng, J. N.; Wang, A. J.; Chen, J. R.; Feng, J. J., Facile Synthesis of

Reduced Graphene Oxide Supported PtAg Nanoflowers and Their Enhanced Electrocatalytic Activity. Int. J. Hydrogen Energy 2014, 39 (7), 3211–3218. 19.

Li, X. R.; Xu, M. C.; Chen, H. Y.; Xu, J. J., Bimetallic Au@Pt@Au Core-Shell

Nanoparticles on Graphene Oxide Nanosheets for High-Performance H2O2 Bi-directional Sensing. J.

Mater. Chem. B 2015, 3 (21), 4355–4362. 20.

Zhou, X.; Qiao, J.; Yang, L.; Zhang, J., A Review of Graphene-Based Nanostructural

Materials for Both Catalyst Supports and Metal-Free Catalysts in PEM Fuel Cell Oxygen Reduction Reactions. Adv. Energy Mater. 2014, 4 (8), 1301523–n/a. 21.

Guo, C. X.; Zhang, L. Y.; Miao, J.; Zhang, J.; Li, C. M., DNA-Functionalized Graphene to

Guide Growth of Highly Active Pd Nanocrystals as Efficient Electrocatalyst for Direct Formic Acid Fuel Cells. Adv. Energy Mater. 2013, 3 (2), 167–171. 22.

Li, J.; Yan, D.; Lu, T.; Qin, W.; Yao, Y.; Pan, L., Significantly Improved Sodium-Ion Storage

Performance of CuS Nanosheets Anchored into Reduced Graphene Oxide with Ether-based Electrolyte. ACS Appl. Mater. Interfaces 2017, 9(3), 2309–2316. 23.

Mohanty, N.; Berry, V., Graphene-based Single-Bacterium Resolution Biodevice and DNA

Transistor: Interfacing Graphene Derivatives with Nanoscale and Microscale Biocomponents. Nano

Lett. 2008, 8 (12), 4469–4476. 24.

Wang, E.; Desai, M. S.; Lee, S. W., Light-Controlled Graphene-Elastin Composite Hydrogel

Actuators. Nano Lett. 2013, 13 (6), 2826–2830. 25.

Lee, Y. M.; Jung, B.; Kim, Y. H.; Park, A. R.; Han, S.; Choe, W. S.; Yoo, P. J., Nanomesh-

Structured Ultrathin Membranes Harnessing the Unidirectional Alignment of Viruses on a GrapheneOxide Film. Adv. Mater. 2014, 26 (23), 3899–3904. 26.

Oh, D.; Dang, X.; Yi, H.; Allen, M. A.; Xu, K.; Lee, Y. J.; Belcher, A. M., Graphene Sheets

Stabilized on Genetically Engineered M13 Viral Templates as Conducting Frameworks for Hybrid Energy-Storage Materials. Small 2012, 8 (7), 1006–1011. 27 | P a g e ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

27.

Cui, Y.; Kim, S. N.; Jones, S. E.; Wissler, L. L.; Naik, R. R.; McAlpine, M. C., Chemical

Functionalization of Graphene Enabled by Phage Displayed Peptides. Nano Lett. 2010, 10 (11), 4559–4565. 28.

Liu, Z.; Chen, S.; Liu, B.; Wu, J.; Zhou, Y.; He, L.; Ding, J.; Liu, J., Intracellular Detection

of ATP Using an Aptamer Beacon Covalently Linked to Graphene Oxide Resisting Nonspecific Probe Displacement. Anal. Chem. 2014, 86 (24), 12229–12235. 29.

Zeng, Q.; Cheng, J. S.; Liu, X. F.; Bai, H. T.; Jiang, J. H., Palladium Nanoparticle/Chitosan-

Grafted Graphene Nanocomposites for Construction of a Glucose Biosensor. Biosens. Bioelectron. 2011, 26 (8), 3456–3463. 30.

Patel, S. K. S.; Choi, S. H.; Kang, Y. C.; Lee, J.-K., Eco-Friendly Composite of Fe3O4-

Reduced Graphene Oxide Particles for Efficient Enzyme Immobilization. ACS Appl. Mater.

Interfaces 2017, 9(3), 2213–2222. 31.

Lee, Y. J.; Lee, Y.; Oh, D.; Chen, T.; Ceder, G.; Belcher, A. M., Biologically Activated

Noble Metal Alloys at the Nanoscale: For Lithium Ion Battery Anodes. Nano Lett. 2010, 10 (7), 2433–2440. 32.

Dang, X.; Yi, H.; Ham, M. H.; Qi, J.; Yun, D. S.; Ladewski, R.; Strano, M. S.; Hammond, P.

T.; Belcher, A. M., Virus-Templated Self-Assembled Single-Walled Carbon Nanotubes for Highly Efficient Electron Collection in Photovoltaic Devices. Nat. Nanotechnol. 2011, 6 (6), 377–384. 33.

Jones, M. R.; Osberg, K. D.; MacFarlane, R. J.; Langille, M. R.; Mirkin, C. A., Templated

Techniques for the Synthesis and Assembly of Plasmonic Nanostructures. Chem. Rev. 2011, 111 (6), 3736–3827. 34.

Lee, B. Y.; Zhang, J.; Zueger, C.; Chung, W. J.; Yoo, S. Y.; Wang, E.; Meyer, J.; Ramesh, R.;

Lee, S. W., Virus-based Piezoelectric Energy Generation. Nat. Nanotechnol. 2012, 7 (6), 351–356. 35.

Yoo, S. Y.; Jin, H. E.; Choi, D. S.; Kobayashi, M.; Farouz, Y.; Wang, S.; Lee, S. W., M13

Bacteriophage and Adeno-Associated Virus Hybrid for Novel Tissue Engineering Material with Gene Delivery Functions. Adv. Healthcare Mater. 2016, 5 (1), 88–93. 36.

Jin, H. E.; Farr, R.; Lee, S. W., Collagen Mimetic Peptide Engineered M13 Bacteriophage for

Collagen Targeting and Imaging in Cancer. Biomaterials 2014, 35 (33), 9236–9245. 37.

Chung, W.-J.; Oh, J.-W.; Kwak, K.; Lee, B. Y.; Meyer, J.; Wang, E.; Hexemer, A.; Lee, S.-

W., Biomimetic Self-Templating Supramolecular Structures. Nature 2011, 478 (7369), 364–368. 38.

Korkmaz, N., Recombinant Bacteriophages as Gold Binding Bio-Templates. Colloids Surf., B

2013, 112, 219–228. 39.

Beech, J.; Saleh, L.; Frentzel, J.; Figler, H.; Correîa, I. R.; Baker, B.; Ramspacher, C.;

Marshall, M.; Dasa, S.; Linden, J.; Noren, C. J.; Kelly, K. A., Multivalent Site-Specific Phage 28 | P a g e ACS Paragon Plus Environment

Page 28 of 32

Page 29 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Modification Enhances the Binding Affinity of Receptor Ligands. Bioconjugate Chem. 2015, 26 (3), 529–536. 40.

Setyawati, M. I.; Xie, J.; Leong, D. T., Phage based Green Chemistry for Gold Ion Reduction

and Gold Retrieval. ACS Appl. Mater. Interfaces 2014, 6 (2), 910–917. 41.

Lee, S. K.; Yun, D. S.; Belcher, A. M., Cobalt Ion Mediated Self-Assembly of Genetically

Engineered Bacteriophage for Biomimetic Co-Pt Hybrid Material. Biomacromolecules 2006, 7 (1), 14–17. 42.

Nam, Y. S.; Park, H.; Magyar, A. P.; Yun, D. S.; Pollom, T. S.; Belcher, A. M., Virus-

Templated Iridium Oxide-Gold Hybrid Nanowires for Electrochromic Application. Nanoscale 2012,

4 (11), 3405–3409. 43.

Lee, S. W.; Belcher, A. M., Virus-based Fabrication of Micro- and Nanofibers Using

Electrospinning. Nano Lett. 2004, 4 (3), 387–390. 44.

Oh, J. W.; Chung, W. J.; Heo, K.; Jin, H. E.; Lee, B. Y.; Wang, E.; Zueger, C.; Wong, W.;

Meyer, J.; Kim, C.; Lee, S. Y.; Kim, W. G.; Zemla, M.; Auer, M.; Hexemer, A.; Lee, S. W., Biomimetic Virus-Based Colourimetric Sensors. Nat. Commun. 2014, 5, 3043(1–8). 45.

Smith, G. P.; Petrenko, V. A., Phage Display. Chem. Rev. 1997, 97 (2), 391–410.

46.

Seo, Y.; Manivannan, S.; Kang, I.; Lee, S.-W.; Kim, K., Gold Dendrites Co-Deposited with

M13 Virus as a Biosensor Platform for Nitrite Ions. Biosens. Bioelectron. 2017, 94, 87–93. 47.

Sambrook, J.; Russell, D. W., Molecular Cloning: A Laboratory Manual. Cold Spring Harbor

Laboratory Press: 2001. 48.

Park, J. P.; Do, M.; Jin, H.-E.; Lee, S.-W.; Lee, H., M13 Bacteriophage Displaying DOPA on

Surfaces: Fabrication of Various Nanostructured Inorganic Materials without Time-Consuming Screening Processes. ACS Appl. Mater. Interfaces 2014, 6 (21), 18653–18660. 49.

Manivannan, S.; Ramaraj, R., Synthesis of Cyclodextrin-Silicate Sol-Gel Composite

Embedded Gold Nanoparticles and its Electrocatalytic Application. Chem. Eng. J. 2012, 210, 195– 202. 50.

Khan, M. M. I.; Haque, A.-M. J.; Kim, K., Electrochemical Determination of Uric Acid in the

Presence of Ascorbic Acid on Electrochemically Reduced Graphene Oxide Modified Electrode. J.

Electroanal. Chem. 2013, 700, 54–59. 51.

Lu, D.; Lin, S.; Wang, L.; Shi, X.; Wang, C.; Zhang, Y., Synthesis of Cyclodextrin-Reduced

Graphene Oxide Hybrid Nanosheets for Sensitivity Enhanced Electrochemical Determination of Diethylstilbestrol. Electrochim. Acta 2012, 85, 131–138.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

52.

Manivannan, S.; Ramaraj, R., Assemblies of Silicate Sol–Gel Matrix Encapsulated

Core/Shell Au/Ag Nanoparticles: Interparticles Surface Plasmon Coupling. J. Nanopart. Res. 2012,

14, 961(1–13). 53.

Manivannan, S.; Ramaraj, R., Electrodeposited Nanostructured Raspberry-like Gold-

Modified Electrodes for Electrocatalytic Applications. J. Nanopart. Res. 2013, 15 (10), 1–13. 54.

Huang, J.; Lin, L.; Sun, D.; Chen, H.; Yang, D.; Li, Q., Bio-Inspired Synthesis of Metal

Nanomaterials and Applications. Chem. Soc. Rev. 2015, 44 (17), 6330–6374. 55.

Lee, H.; Dellatore, S. M.; Miller, W. M.; Messersmith, P. B., Mussel-Inspired Surface

Chemistry for Multifunctional Coatings. Science 2007, 318 (5849), 426–430. 56.

Manivannan, S.; Kim, K., Electrochemical Biosensor Utilizing Supramolecular Association

of Enzyme on Sol−gel Matrix Embedded Gold Nanoparticles Supported Reduced Graphene Oxide−cyclodextrin Nanocomposite. Electroanalysis 2016, 28 (7), 1608–1616. 57.

Dai, L.; Zhao, Y.; Chi, Q.; Liu, H.; Li, J.; Huang, T., Morphological Control and Evolution of

Octahedral and Truncated Trisoctahedral Pt-Au Alloy Nanocrystals Under Microwave Irradiation.

Nanoscale 2014, 6 (17), 9944–9950. 58.

Rodriguez, P.; Kwon, Y.; Koper, M. T. M., The Promoting Effect of Adsorbed Carbon

Monoxide on the Oxidation of Alcohols on a Gold Catalyst. Nat. Chem. 2012, 4 (3), 177–182. 59.

Zhu, C.; Guo, S.; Dong, S., Rapid, General Synthesis of PdPt Bimetallic Alloy Nanosponges

and Their Enhanced Catalytic Performance for Ethanol/Methanol Electrooxidation in an Alkaline Medium. Chem. Eur. J. 2013, 19 (3), 1104–1111. 60.

Cui, Z.; Yang, M.; DiSalvo, F. J., Mesoporous Ti0.5Cr0.5N Supported PdAg Nanoalloy as

Highly Active and Stable Catalysts for the Electro-oxidation of Formic Acid and Methanol. ACS

Nano 2014, 8 (6), 6106–6113. 61.

Liu, Z.; Zhao, B.; Guo, C.; Sun, Y.; Xu, F.; Yang, H.; Li, Z., Novel Hybrid Electrocatalyst

with Enhanced Performance in Alkaline Media: Hollow Au/Pd Core/Shell Nanostructures with a Raspberry Surface. J. Phys. Chem. C 2009, 113 (38), 16766–16771. 62.

Manivannan, S.; Kang, I.; Kim, K., In Situ Growth of Prussian Blue Nanostructures at

Reduced Graphene Oxide as a Modified Platinum Electrode for Synergistic Methanol Oxidation.

Langmuir 2016, 32 (7), 1890–1898. 63.

Wang, Z.; Shi, G.; Xia, J.; Xia, Y.; Zhang, F.; Xia, L.; Song, D.; Liu, J.; Li, Y.; Xia, L.; Brito,

M. E., Facile Preparation of a Pt/Prussian Blue/Graphene Composite and its Application as an Enhanced Catalyst for Methanol Oxidation. Electrochim. Acta 2014, 121, 245–252.


Page 30 of 32

Page 31 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


64.

Zhang, C. W.; Xu, L. B.; Chen, J. F., High Loading Pt Nanoparticles on Ordered Mesoporous

Carbon Sphere Arrays for Highly Active Methanol Electro-Oxidation. Chin. Chem. Lett. 2016, 27 (6), 832–836. 65.

You, H.; Zhang, F.; Liu, Z.; Fang, J., Free-Standing Pt–Au Hollow Nanourchins with

Enhanced Activity and Stability for Catalytic Methanol Oxidation. ACS Catal. 2014, 4 (9), 2829– 2835.



Graphical abstract:

CH3OH Mass activity / A mg–1Pt

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 32 of 32

1.5

1.0

a : Au b : Pt c : Au–Pt

c

0.5

0.0

b a

-1000-800 -600 -400 -200 0 200 400 600

E vs. Ag/AgCl (mV)

–

CO2 + H2O + 6e

SSG/M13Y3E/rGO/(Au–Pt) Catalyst


M13 Virus-Incorporated Biotemplates on Electrode ... - ACS Publications

Recommend Documents