Surface-plasmon-enhanced photo-electrocatalytic ethylene glycol

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Surface-plasmon-enhanced photo-electrocatalytic ethylene glycol oxidation based on highly open AuAg nanobowls Hui Xu, Pingping Song, Bo Yan, Jin Wang, Jun Guo, and Yukou Du ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.7b04560 • Publication Date (Web): 22 Jan 2018 Downloaded from http://pubs.acs.org on January 26, 2018

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ACS Sustainable Chemistry & Engineering

Surface-Plasmon-Enhanced Photo-Electrocatalytic Ethylene Glycol Oxidation Based on Highly Open AuAg Nanobowls Hui Xu†, Pingping Song†, Bo Yan†, Jin Wang†, Jun Guo ‡, and Yukou Du*† †

College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China ‡

Testing & Analysis Center, Soochow University, 199 Renai Road, Jiangsu 215123, China

* Corresponding author: Tel: 86-512-65880089, Fax: 86-512-65880089; E-mail: [email protected] (Y. Du). ABSTRACT Plasmonic metal nanocatalysts can be employed to efficiently boost the conventional catalytic reaction through the energy of photons. This work has demonstrated a facile ultrasonic-assisted galvanic replacement method to successfully fabricate the highly open AuAg nanobowls with tunable atomic ratio, which act as the catalytically active site and the light absorbers simultaneously. By virtue of the synergistic and electronic effect between Au and Ag, as well as unique bowl-like structure, the resulted AuAg nanobowls exhibit superior electrocatalytic performances towards ethylene glycol oxidation than that of the bare Au. More interestingly, such AuAg nanobowls also show the surface plasmon resonance (SPR)-induced enhancement of electrocatalytic performances when the modified electrodes are upon the visible light irradiation, 2.3 times higher than that in the traditional ambient electrocatalytic oxidation. This finding opens a new way for designing a myriad of plasmonic metal nanocatalysts with desirable nanostructures for solar fuel cells and other devices.

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Keywords: Highly open; AuAg nanobowls; Visible light; Surface plasmon resonance; Ethylene glycol electrooxidation INTRODUCTION The rapid consumption of traditional fossil fuel accompanying with lots of serious problems such as energy crisis and environmental pollution.1 Therefore, researching for a promising technology for future alternative energy sources has been urgently sought.2 The solar energy is by far the most abundant energy source of clean, economical and sustainable energy, which can be well conversed into the clean electrical energy through photoelectrocatalysis.3 Efficient harvesting of solar energy has now been one of the hottest worldwide research aspects, for which can alleviate some serious problems such as energy shortage and environmental pollution to some extent.4 Among various technologies, the use of sun light to boost some typical physiochemical reactions such as photocatalytic liquid fuel oxidation reaction in fuel cells by the photocatalysts has received increasing notices, where photo-responsive plasmonic metal nanostructures have been well applied to serve as the highly efficient photocatalysts for fuel cells due to the fact that the excitation of surface plasmons resonance (SPR) can assist them in efficiently harvesting visible light.5 In addition, both the elastic radiative re-emission of photons and the formation of energetic hot electrons can also decay surface plasmons (SPs), and thus transformed the electrons to the adsorbate acceptor states or relaxed by locally heating the nanostructure. Therefore, the excited plasmonic metal nanostructures can significantly enhance the conventional heterogeneous catalysis via harvesting visible light and greatly enhance the electrocatalytic performances in fuel cells.6


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Nevertheless, little efforts have been paid for employing the solar energy to promote electrocatalytic oxidation of liquid fuel due to the absence of SPR effect over noble Pd and Pt (promising electrocatalysts for fuel cells), which has thus seriously inhibited the solar energy utilization for fuel cells.7-10 Impressively, different from the noble Pt and Pd, the Au nanostructures can adsorb a wide arrange of visible light due to their broadly tunable aspectratio-dependent longitudinal SPR (LSPR).11-12 In addition, it has also been well demonstrated that the Au materials at the nanoscale can also greatly boost the liquid fuel electrooxidation in the alkaline media with high performance due to their many excellent properties such as magnetic and optical properties (quantum size effects) and so on.13-14 Accordingly, when coupled Au with a second transition metal to form the bimetal heterostructures would simultaneously serve as both the catalytically active site and light absorber.15-17 Among various transition metals, Ag has attracted numerous focuses due to the facts that alloying with Ag can simultaneously boost the activation of surface active sites of Au and the intermediate oxidation.18-19 It has also been reported that the particle size, crystal structure especially morphology of cocatalyst can also significantly affect the photoelectrocatalytic activity.

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The catalysts with

fascinating nanostructures, generally, may have many defects, lack the long-range atomic order and provide more surface active areas, which thus allow for harvesting visible light, boosting the charge transfer and exposing more active sites for photocatalytic reaction.25 The highly open bowl-like nanostructure, with the advantages of high surface to volume ratio and large void space can offer 3D catalytic surfaces and high utilization of precious metals, which have attracted the increasing research interests for recent years.26-28 Along this direction, if we can construct the unique binary AuAg nanocrystals with highly open structure to act as both the


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catalytically active site and light absorber, it will be extremely favorable for the great enhancements of electrocatalytic performances of liquid fuel oxidation.29 In accordance with these guidelines, we herein demonstrated an ultrasonic-assisted galvanic replacement method to successfully synthesize the bowl-like AuAg nanocatalysts with rough open surfaces. Impressively, by virtue of the unique structure, alloy and electronic effect, as well as the SPR effect, the resulted AuAg nanocatalysts displayed outstandingly superior electrocatalytic activity towards ethylene glycol oxidation reaction (EGOR) under the visible light irradiation with the mass activity of 5653.1 mA mgAu-1. Impressively, the as-prepared bowllike AuAg nanocatalysts displayed 2.3-fold enhancements in mass activity for EGOR when compared to traditional electrocatalytic reaction. EXPERIMENTAL SECTION Preparation of highly open AuAg nanobowls The preparation of the Ag seeds with the assistance of sodium citrate and tannic acid has been fully described in our previous work.30 In the strandard synthese of highly open AuAg nanobowls, 10 mg hexadecyl trimethyl ammonium chloride (CTAC) and 60 mg AA were firstly dissolved into 5 mL deionized water, after that, 0.40 mL HAuCl4 (24.3 mM) was injected into above aqueous solution with rapid magnetic stirring. After 10 min vigorous stirring, different volumes of freshly prepared Ag seeds were added into above glass vial. The galvanic replacement reaction between Ag seed and HAuCl4 was then occurred with the assistance of continuous sonicate for another two hours. The atomic ratio of such AuAg nanobowls can be easily tuned via adding different volumes of Ag seeds in the mixture. Instruments


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In this work, we firstly used the Tecnai G220 (FEI America) to investigate the morphology and structure of the samples. After that, the FEI Tecnai F20 transmission electron microscope (TEM), scanning electron microscope (SEM), X’Pert-Pro MPD diffractometer (XRD, Netherlands PANalytical) with a Cu Kα X-ray source (λ = 1.540598 Å) and X-ray photoelectron spectroscopy (XPS) performed on a VG Scientific ESCALab 220XL electron spectrometer using 300 W Al Kα radiation have also been employed. All the electrochemical tests were conducted in a standard electrochemical workstation (CHI 760E), including a typical three-electrode system. And the electrocatalytic activity of the EGOR was carried out in the quartz beaker including 1 M KOH and 1 M EG solution at the scanning rate of 50 mV/s from 0.3 to 1.7 V (vs RHE). Chronoamperometry (CA) and photocurrent responses of the AuAg and Au modified electrodes under visible light irradiation or dark were measured at 1.05 V. The electrochemical impedance spectroscopy (EIS) measurements were taken in frequency range of 100 kHz-1 Hz at 0.25 V with an AC amplitude of 5 mV. The catalysts-modified electrode can be prepared via adding 10 µL of well-dispersed catalyst ink to the glassy carbon electrode (GCE) and dried at room temperature, 1.0 mL of 5 wt % nafion solution was then dropped to the surface of GCE for further avoiding the dissolution of catalysts inks. Their long-term stability can be investigated via carrying out the successive cyclic voltammetry (CV) of 500 cycles. It was worth noting that all the visible light photo-electrochemical measurements can be operated by using a xenon lamp (150 W) with UV cut–off filter (>400 nm) to irradiate all the working electrodes. RESULTS AND DISCUSSION Experimentally, these highly open AuAg nanobowls were synthesized by the ultrasonicassisted galvanic replacement reaction between Ag seeds and HAuCl4. For exploring the morphology of the as-prepared AuAg nanocrystals, the samples were firstly investigated by


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TEM and SEM. As it can be seen in Figure 1A, Figure 1B and Figure S1, it is clearly observed that the products consist of the uniform nanocrystals of bowl-like nanostructure with many interconnected edges and a large number of branches, confirming the high-yield syntheses.31 The bowl-like nanocrystals are also highly dispersed without aggregation and the mean size was calculated to be 49.2 nm with a narrow size distribution (shown in Figure S2). After a close observation, we may find that each AuAg nanobowl possesses the similar solid wall with the diameter around 10 nm. The high surface to volume ratio and large void space for such highly open AuAg nanobowls can thus offer more catalytic surfaces and high utilization of precious metals.32-33


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Figure 1. The morphology and structure characterizations of AuAg nanobowls. (A and B) representative TEM images with different magnifications, (C) XRD patterns, (D) HRTEM image, (E) HAADF-STEM image and elemental mappings, and (F) corresponding line-scans of the AuAg nanobowls. An XRD analysis was also undertaken to investigate the lattice constant of the as-prepared AuAg nanoctystals. As shown in Figure 1C, remarkably, the XRD patterns could be indexed to the face-centered cubic (fcc) crystalline Au.34 More interestingly, each XRD diffraction peak located between the standard Au and Ag, implying the formation of AuAg alloy phase in such AuAg nanobowls.35 Figure 1D showed the HRTEM image of the as-prepared AuAg nanobowls, notably, the calculated lattice distance was 0.24 nm, which could be assigned to the Au (111) facet. This result further suggests the formation of AuAg alloy in the AuAg nanobowls. The energy dispersive X-ray spectroscopy (EDS) mappings shown in Figure 1E showed that both the elements of Au and Ag were homogeneously distributed throughout the whole nanobowl, as further demonstrated by the line-scans (Fig1F), indicating the alloy structure of AuAg nanobowls.

Figure 2. XPS spectra of (A) Au 4f and (B) Ag 3d in Au1Ag1 nanobowls.


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To confirm the component of such AuAg nanobowls, the XPS spectra were also measured. As shown in Figure 2A, the two strong peaks presented at binding energy (B.E.) of 87.49 and 83.78 eV were well assigned to metallic Au 4f 5/2 and 4f 7/2, respectively, indicating the complete reduction of AuCl4− to Au0.36 From the Figure 2B, we can observe that the metallic Ag is also the predominate product in such Au1Ag1 nanobowl catalysts, demonstrating the efficient reduction of Ag ions.37 Notably, compared with the monometal Au and Ag, the B.E. of Au and Ag in such Au1Ag1 nanobowl catalysts showed a slight shift, indicating the changes in the electronic structure due to the occurrence of charge transfer between Au and Ag.35 For uncovering the influence of atomic ratio on the final shape of the AuAg nanocrystals, the Au1Ag0.5 and Au1Ag1.5 nanocrystals were also prepared at the same conditions while tuning the amount of Ag seeds. As it can be seen in Figure 3A and Figure 3C, similar with the Au1Ag1, both Au1Ag0.5 and Au1Ag1.5 showed the typical bowl-like nanostructure with a concave property. Figure 3B and Figure 3D have further demonstrated that both Au and Ag were also homogeneously distributed throughout the whole nanobowl, suggesting the formation of alloy phase in the Au1Ag0.5 and Au1Ag1.5. This result implies that such ultrasonic-assisted galvanic replacement method can be well applied to synthesize the highly open AuAg nanobowls regardless of the variation of atomic ratio.38


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Figure 3. The morphology characterizations of Au1Ag0.5 and Au1Ag1.5 nanobowls. Representative TEM images of (A) Au1Ag0.5 and (C) Au1Ag1.5 nanobowls, HRTEM image and elemental mappings of (B) Au1Ag0.5 and (D) Au1Ag1.5 nanobowls. To gain the comprehensive insights into the formation mechanism, a battery of controlled experiments have also been further carried out. Firstly, the bare Au nanoparticles prepared via the same method just without the addition of Ag seeds have also been researched. As it can be seen


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in Figure S3, the main products for bare Au are irregular nanosphere structures. And the bare Au showed an absorption edge at ca. 520 nm, revealing the distinct absorptions of visible light. As it has been demonstrated that CTAC can efficiently absorb on the Au (100) facet to affect the final shape by the anisotropic interactions between the solid solution and CTAC.39 Accordingly, for studying the influence of CTAC on the morphology of such AuAg NCs, the AuAg NCs have also been prepared in the absence CTAC while kept other conditions the same. As shown in Figure S4, no apparent hollow and bowl-like AuAg nanostructures could be observed in the absence of CTAC, suggesting that CTAC in this work played a crucial role in controlling the final bowl-like nanostructures.18 For analyzing the optical properties of the as-obtained highly open AuAg nanobowls, the UV–vis adsorption spectra of AuAg samples were also measured, as is displayed in Figure 4A. The AuAg nanobowls showed an absorption edge at ca. 432 nm, revealing the distinct absorptions of visible light. This result has thus further suggested that the products possess promising superiorities for acting as the ideal phtoelectrocatalysts towards EGOR with the assistance of visible light.15 In addition, we also utilized the K3[Fe(CN)6/K4[Fe(CN)6] (1:1) mixture as the typical redox probe to study the charge transfer of AuAg nanocatalysts during the photoreactions. As it can be seen in Figure 4B, both the Au1Ag1 and bare Au modified electrodes showed the typical CV responses of reversible redox couple of Fe(CN)64−/Fe(CN)63−. Remarkably, the Au1Ag1 modified electrode shifted slightly to a lower potential when compared with bare Au, moreover, such Au1Ag1 modified electrode also showed enhanced redox peak current, indicating the better reversibility of AuAg nanocatalysts.40-41


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Figure 4. (A) UV-vis spectra of AuAg nanobowls, (B) CVs of the bare Au and Au1Ag1 electrodes in a 2.5 mM K3[Fe(CN)6/K4[Fe(CN)6] and 0.1 M KCl solution at a potential of 1.1V. Considering the unique properties of such highly open AuAg nanobowls, such as high surface per unit volume, large void space and 3D catalytic surfaces, which would thus be highly expected to display outstandingly high electrocatalytic performances towards liquid fuel oxidations. In this regard, we herein chose the EGOR as the model reaction system to evaluate their electrocatalytic performances.42 The electrocatalytic activities of these electrocatalysts were initially evaluated via CV under dark or visible light illumination in 1 M KOH and 1 M EG solution. As shown in Figure 5A and Figure 5B, the onset potential on the AuAg modified electrode under visible light irradiation shift negatively to a smaller potential compared to that under the ambient reaction, suggesting that EG can be easier oxidized on the AuAg modified electrodes under the visible light illumination.43 Moreover, as shown in Figure 5C, at a given potential of 1.05 V, the Au1Ag1 modified electrode displayed the highest current density of 5653.1 mA mg-1 under the visible light illumination, which was ca. 2.3, 5.7 and 9.4 times higher than that of Au1Ag1 without light irradiation (2473.6 mA mg−1), bare Au under light irradiation (991.8 mA mg−1) and bare Au under ambient reaction (603.2 mA mg−1), respectively. In addition,


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the Au1Ag0.5 (3933.9 mA mg−1) and Au1Ag1.5 (2496.4 mA mg−1) modified electrodes under the visible light illumination also displayed the 2.02 and 1.93-fold enhancements on mass activity than that under the ambient oxidation reaction, respectively. As seen from the Figure S5, the AuAg nanobowls also displayed superior electrocatalytic activity than that of the commercial Pt/C (992.3 mA mg−1) and Pd/C (778.5 mA mg−1). These superior photoelectrocatalytic properties under visible light irradiation could be attributed to the fact that abundant surface active areas originated from the nanobowl structure and the photogenerated charges occurred by SPR effect.44-46

Figure 5. (A) CV curves of bare Au and Au1Ag1 towards EGOR under visible light illumination and dark. (B) CV curves of Au1Ag0.5 and Au1Ag1.5 catalysts towards EGOR under visible light


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illumination and dark. (C) The calculated mass activities of bare Au, Au1Ag1, Au1Ag0.5 and Au1Ag1.5 catalysts towards EGOR under visible light illumination and dark. (D) Photocurrent responses of Au1Ag1 towards EGOR in 1.0 M EG and 1.0 M KOH solution at a potential of 1.05 V under visible light illumination. The illumination from a Xe lamp was interrupted every 100 s. For further investigating the photoelectric properties of the resulted Au1Ag1 nanobowls, we have also conducted the photocurrent response. Figure 5D showed photocurrent–time (I–t) curve on the Au1Ag1 modified electrode. Remarkably, a responsive photocurrent with intensity of ca.200 mA mg-1 was observed when the electrode was upon visible light illumination. Besides, the photocurrent response was also repeatable during on/off cycles upon light illumination. However, as it can be seen in Figure S6, the responsive photocurrent for bare Au showed a lower intensity of ca.30 mA mg-1, indicating that the alloy and electronic effects between Au and Ag were favorable for the enhancement of current density.11


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Figure 6. (A) CV curves of EGOR on Au1Ag1 nanobowls modified electrodes at different scan rates. (B) the corresponding plot of forward peak current (If) versus the square root of the scan rate (v1/2). (C) Nyquist plots of bare Au and Au1Ag1 towards EGOR under visible light illumination and dark. (D) Nyquist plots of Au1Ag0.5 and Au1Ag1.5 catalysts towards EGOR under visible light illumination and dark at the potential of 1.1 V. On the purpose of studying the reaction process of EGOR on the surface of Au1Ag1 modified electrodes under visible light illumination, the scan rates ranging from 100 to 500 mV/s were also conducted to investigate the influences of scan rates on the forward peak current density. Figure 6A showed that the current density for the EGOR occurred on the surface of electrode raised over the scan rate. Besides, the potential corresponded to peak current also shifted


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positively. Figure 6B showed the linear relationship of peak current density (jm) with the square root of the scan rate (v1/2). This result revealed that the EGOR on the Au1Ag1 modified electrodes under visible light illumination followed a diffusion-controlled process, and the high slope value further indicated the enhanced electrooxidation kinetic of Au1Ag1 nanobowls.36, 47 The EIS measurement conducted at the potential of 1.1 V has also been employed to study their electrochemical reaction process, for which the diameter is a crucial parameter to evaluate the electrical conductivity of the as-prepared electrocatalysts.48-49 As it can be observed in Figure 6CD, the diameter impedance arc (DIA) of bare Au and AuAg nanocatalysts with different compositions under visible light illumination were much smaller than that under dark, respectively, and Au1Ag1 modified electrode displayed the smallest DIA, indicating that such AuAg nanocatalysts possessed the smaller electron transfer resistance and best electrical conductivity under visible light illumination, which was attributed to the SPR effect and the charge transfer.50 In the alkaline media, the (CH2OH)2 can be easily oxidized to the nontoxic C2O42- but not CO on the AuAg electrode under the visible light illumination.42, 51-52


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Figure 7. (A) CA curves of bare Au, Au1Ag1 under visible light and dark towards EGOR at the fixed potential of 1.05 V. (B) CA curves of Au1Ag0.5 and Au1Ag1.5 catalysts under visible light and dark towards EGOR at the fixed potential of 1.05 V. (C) Long-term stability comparison of bare Au, Au1Ag1 under visible light and dark towards EGOR for successive CVs of 500 cycles,


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and (D) Long-term stability comparison of Au1Ag0.5 and Au1Ag1.5 under visible light and dark towards EGOR for successive CVs of 500 cycles. (E) The normalized current densities of bare Au, Au1Ag1, Au1Ag0.5 and Au1Ag1.5 under visible light and dark electrocatalysts after CA measurement for 3600 s, (F) the normalized current densities of bare Au, Au1Ag1, Au1Ag0.5 and Au1Ag1.5 under visible light and dark after successive CVs of 500 cycles. The durability of catalyst is also another significant parameter to evaluate the properties of electrocatalyst in fuel cells. An electrocatalyst with better durability means a much longer lifetime, which is crucial for practical commercial applications. To this end, we here conducted the CA measurement for 3600 s with and without visible light illumination at the fixed potential of 1.05 V to determine their electrocatalytic durability. As it can be seen in Figure 7A and Figure 7B, the electrodes exhibited excellent electrocatalytic performances, although gradually degraded due to some dissolution or partial poisoning of catalysts. As illustrated in Figure 7E, the steady–state of oxidation current density of all electrodes under the visible light illumination after 3600 s were further enhanced than that under dark, and the Au1Ag1 electrode under the visible light illumination possessed the highest retained current density of 625.4 mA mg-1, 51.7 times higher than that bare Au under dark (12.1 mA mg-1). Apart from these, for further evaluating their stability, the successive CVs of 500 cycles have also been conducted. Figure 7C and Figure 7D showed the normalized current of EGOR in the forward scan vs the cycle number of the CV scan on bowl-like AuAg nanocrystals and bare Au electrodes 1 M KOH and 1 M EG solution with the scanning rate of 50 mV/s, as seen, the bowl-like Au1Ag1 electrode under the visible light illumination possess the superior long-term stability with less decay after 500 cycles.53 For a detailed comparison, the normalized current of these electrocatalysts have also been recorded in Figure 7F, as observed, similar to the CA measurements, all the electrodes


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under the visible light illumination possessed the higher normalized current than that under dark, and the bowl-like Au1Ag1 electrode under the visible light illumination still possessed the highest normalized current of 41.8 %, further confirming the great enhancement of durability.54 These findings imply that such bowl-like AuAg electrodes possess more durable and higher catalytic performance towards EGOR, which are also consistent with the above CVs and EIS measurements. In general, the as-obtained bowl-like AuAg nanocatalysts electrode under visible light illumination displayed great enhancements on the electrocatalytic performances towards EGOR, which are mainly ascribed to: (1) the intimate integration of plasmonic Au with Ag through galvanic replacement can efficient harvest visible light for the electrocatalytic reactions on the nanostructures.56 (2) The plasmon-induced interfacial interaction within bowl-like AuAg nanostructures is also a significant factor for the plasmon-enhanced catalytic activity towards EGOR.57, 58 (3) The synergistic role and electronic effect among Au and Ag are also benefitting for the enhancement of electrocatalytic performances.59, 60 CONCLUSIONS In summary, a facile ultrasonic-assisted galvanic replacement reaction has been well developed to synthesize the highly open AuAg nanobowl nanocatalysts. The as-prepared bowllike AuAg nanocataysts displayed superior electrocatalytic ability for EGOR than that of bare Au. More interestingly, when the AuAg modified electrodes were upon visible light irradiation, obtained 2.3-fold enhancements of activity towards EGOR when compared with the traditional electrocatalytic oxidation reaction. The synergistic effect and electronic effect between Au and Ag, the more exposed surface active sites together with the efficient SPR effect contribute the


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great enhancements of electrocatalytic performances. Given the ease design of nanomaterials, as well as the availability of many unique nanostructures with more exposed surface active areas, there seems to show great potential for fabricating a myriad of nanomaterials for solar fuel cells and other devices. ASSOCIATED CONTENT Supporting Information Figure S1 Representative SEM images of AuAg nanobowls. Figure S2 Size distribution of AuAg nanocrystals. Figure S3 (A and B) Typical TEM images of bare Au and (C) its UV-vis spectra. Figure S4 TEM images of AuAg nanocrystals prepared in the absence of CTAC while kept other conditions the same. Figure S5 (A) CV curves of commercial Pd/C and Pt/C operated in 1 M KOH + 1 M EG solution. (B) Calculated mass activities of commercial Pd/C and Pt/C towards EGOR. Figure S6 Photocurrent responses of bare Au towards EGOR were in 1.0 M EG and 1.0 M KOH solution at a potential of 1.05 V under visible light illumination. The illumination from a Xe lamp was interrupted every 100 s.

AUTHOR INFORMATION Corresponding Author Tel: 86-512-65880089, Fax: 86-512-65880089; E-mail: [email protected] (Y. Du). Author Contributions


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The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. All authors have given approval to the final version of the manuscript. Notes The authors declare no competing financial interest. ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China (Grant No. 51373111), the Suzhou Industry (SYG201636), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and the State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials. REFERENCES 1.

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For Table of Content Use Only The alloy and electronic effect, as well as the surface plasmon resonance effect of electro-and photo-catalytic ethylene glycol oxidation of bowl-like AuAg nanostructures contribute to the enhancements of electrocatalytic performances under the visible light irritation.


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Surface-plasmon-enhanced photo-electrocatalytic ethylene glycol

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