1. Collaborative Innovation Center of Chemical Science and Engineering, Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 2. Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
Novel, hierarchical, flower-like Ag/Cu2O and Au/Cu2O nanostructures were successfully fabricated and applied as efficient electrocatalysts for the electrochemical reduction of CO2. Cu2O nanospheres with a uniform size of ~180 nm were initially synthesized. Thereafter, Cu2O was used as a sacrificial template to prepare a series of Ag/Cu2O composites through galvanic replacement. By varying the Ag/Cu atomic ratio, Ag0.125/Cu2O, having a hierarchical, flower-like nanostructure with intersecting Ag nanoflakes encompassing an inner Cu2O sphere, was prepared. The as-prepared Agx/Cu2O samples presented higher Faradaic efficiencies (FE) for CO and relatively suppressed H2 evolution than the parent Cu2O nanospheres due to the combination of Ag with Cu2O in the former. Notably, the highest CO evolution rate was achieved with Ag0.125/Cu2O due to the larger electroactive surface area furnished by the hierarchical structure. The same hierarchical flower-like structure was also obtained for the Au0.6/Cu2O composite, where the FECO (10%) was even higher than that of Ag0.125/Cu2O. Importantly, the results reveal that Ag0.125/Cu2O and Au0.6/Cu2O both exhibit remarkably improved stability relative to Cu2O. This study presents a facile method of developing hierarchical metal-oxide composites as efficient and stable electrocatalysts for the electrochemical reduction of CO2.
Z Jin, P Li, G Liu, B Zheng, H Yuan, D Xiao. Enhancing catalytic formaldehyde oxidation on CuO–Ag2O nanowires for gas sensing and hydrogen evolution. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2013, 1(46): 14736–14743 https://doi.org/10.1039/c3ta13277c
2
J Park, J Liu, H Peng, L Figueroa-Cosme, S Miao, S Choi, S Bao, X Yang, Y Xia. Coating Pt–Ni octahedra with ultrathin Pt shells to enhance the durability without compromising the activity toward oxygen reduction. ChemSusChem, 2016, 9(16): 2209–2215 https://doi.org/10.1002/cssc.201600566
3
H Liu, C Koenigsmann, R R Adzic, S S Wong. Probing ultrathin one-dimensional Pd-Ni nanostructures as oxygen reduction reaction catalysts. ACS Catalysis, 2014, 4(8): 2544–2555 https://doi.org/10.1021/cs500125y
4
Y Wang, J Zhang. Structural engineering of transition metal-based nanostructured electrocatalysts for efficient water splitting. Frontiers of Chemical Science and Engineering, 2018, 12(4): 838–854 https://doi.org/10.1007/s11705-018-1746-3
5
X Qu, R Yang, F Tong, Y Zhao, M Wang. Hierarchical ZnO microstructures decorated with Au nanoparticles for enhanced gas sensing and photocatalytic properties. Powder Technology, 2018, 330: 259–265 https://doi.org/10.1016/j.powtec.2018.02.019
6
Y Su, H Guo, Z Wang, Y Long, W Li, Y Tu. Au@Cu2O core-shell structure for high sensitive non-enzymatic glucose sensor. Sensors and Actuators. B, Chemical, 2018, 255: 2510–2519 https://doi.org/10.1016/j.snb.2017.09.056
7
M Pang, Q Wang, H C Zeng. Self-Generated etchant for synthetic sculpturing of Cu2O-Au, Cu2O@Au, Au/Cu2O, and 3D-Au Nanostructures. Chemistry (Weinheim an der Bergstrasse, Germany), 2012, 18(46): 14605–14609 https://doi.org/10.1002/chem.201202765
8
T S Rodrigues, A G M Da Silva, R S Alves, I C de Freitas, D C Oliveira, P H C Camargo. Controlling reduction kinetics in the galvanic replacement involving metal oxides templates: Elucidating the formation of bimetallic bowls, rattles, and dendrites from Cu2O Spheres. Particle & Particle Systems Characterization, 2018, 35(5): 1700175–1700184 https://doi.org/10.1002/ppsc.201700175
9
H Zhu, M Du, D Yu, Y Wang, M Zou, C Xu, Y Fu. Selective growth of Au nanograins on specific positions (tips, edges and facets) of Cu2O octahedrons to form Cu2O–Au hierarchical heterostructures. Dalton Transactions (Cambridge, England), 2012, 41(45): 13795–13799 https://doi.org/10.1039/c2dt31487h
10
L Polavarapu, D Zanaga, T Altantzis, S Rodal-Cedeira, I Pastoriza-Santos, J Pérez-Juste, S Bals, L M Liz-Marzán. Galvanic replacement coupled to seeded growth as a route for shape-controlled synthesis of plasmonic nanorattles. Journal of the American Chemical Society, 2016, 138(36): 11453–11456 https://doi.org/10.1021/jacs.6b06706
11
H Zhu, M L Du, D L Yu, Y Wang, L N Wang, M L Zou, M Zhang, Y Fu. A new strategy for the surface-free-energy-distribution induced selective growth and controlled formation of Cu2O–Au hierarchical heterostructures with a series of morphological evolutions. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2013, 1(3): 919–929 https://doi.org/10.1039/C2TA00591C
12
Y Zhang, X Zhou, Y Zhao, Z Liu, D Ma, S Chen, G Zhu, X Li. One-step solvothermal synthesis of interlaced nanoflake-assembled flower-like hierarchical Ag/Cu2O composite microspheres with enhanced visible light photocatalytic properties. Royal Society of Chemistry Advances, 2017, 7(12): 6957–6965 https://doi.org/10.1039/C6RA26870F
13
J Wang, H Wang, Z Han, J Han. Electrodeposited porous Pb electrode with improved electrocatalytic performance for the electroreduction of CO2 to formic acid. Frontiers of Chemical Science and Engineering, 2015, 9(1): 57–63 https://doi.org/10.1007/s11705-014-1444-8
14
G Song, X Wu, F Xin, X Yin. ZnFe2O4 deposited on BiOCl with exposed (001) and (010) facets for photocatalytic reduction of CO2 in cyclohexanol. Frontiers of Chemical Science and Engineering, 2017, 11(2): 197–204 https://doi.org/10.1007/s11705-016-1606-y
15
H Xie, J Wang, K Ithisuphalap, G Wu, Q Li. Recent advances in Cu-based nanocomposite photocatalysts for CO2 conversion to solar fuels. Journal of Energy Chemistry, 2017, 26(6): 1039–1049 https://doi.org/10.1016/j.jechem.2017.10.025
16
T Qin, Y Qian, F Zhang, B Lin. Cloride-derived copper electrode for efficient electrochemical reduction of CO2 to ethylene. Chinese Chemical Letters, 2019, 30(2): 314–318 https://doi.org/10.1016/j.cclet.2018.07.003
17
J He, N J J Johnson, A Huang, C P Berlinguette. Electrocatalytic alloys for CO2 reduction. ChemSusChem, 2018, 11(1): 48–57 https://doi.org/10.1002/cssc.201701825
18
S Singh, R K Gautam, K Malik, A Verma. Ag-Co bimetallic catalyst for electrochemical reduction of CO2 to value added products. Journal of CO2 Utilization, 2017, 18: 139–146
19
D Kim, J Resasco, Y Yu, A M Asiri, P Yang. Synergistic geometric and electronic effects for electrochemical reduction of carbon dioxide using gold–copper bimetallic nanoparticles. Nature Communications, 2014, 5(1): 5948–5956 https://doi.org/10.1038/ncomms5948
20
J Yang, X Liu, H Cao, Y Shi, Y Xie, J Xiao. Dendritic BiVO4 decorated with MnOx co-catalyst as an efficient hierarchical catalyst for photocatalytic ozonation. Frontiers of Chemical Science and Engineering, 2019, 13(1): 185–191 https://doi.org/10.1007/s11705-018-1713-z
21
B Zhang, J Zhang. Rational design of Cu-based electrocatalysts for electrochemical reduction of carbon dioxide. Journal of Energy Chemistry, 2017, 26(6): 1050–1066 https://doi.org/10.1016/j.jechem.2017.10.011
22
J Kim, H Woo, S Yun, H Jung, S Back, Y Jung, Y Kim. Highly active and selective Au thin layer on Cu polycrystalline surface prepared by galvanic displacement for the electrochemical reduction of CO2 to CO. Applied Catalysis B: Environmental, 2017, 213: 211–215 https://doi.org/10.1016/j.apcatb.2017.05.001
23
M Kuo, C Hsiao, Y Chiu, T Lai, M Fang, J Wu, J Chen, C Wu, K Wei, H Lin, Y Hsu. Au@Cu2O core@shell nanocrystals as dual-functional catalysts for sustainable environmental applications. Applied Catalysis B: Environmental, 2019, 242: 499–506 https://doi.org/10.1016/j.apcatb.2018.09.075
24
S Lee, G Park, J Lee. Importance of Ag-Cu biphasic boundaries for selective electrochemical reduction of CO2 to ethanol. ACS Catalysis, 2017, 7(12): 8594–8604 https://doi.org/10.1021/acscatal.7b02822
25
W Jin, P Xu, L Xiong, Q Jing, B Zhang, K Sun, X Han. SERS-active silver nanoparticle assemblies on branched Cu2O crystals through controlled galvanic replacement. Royal Society of Chemistry Advances, 2014, 4(96): 53543–53546 https://doi.org/10.1039/C4RA10045J
26
S Chen, P Liu, K Su, X Li, Z Qin, W Xu, J Chen, C Li, J Qiu. Electrochemical aptasensor for thrombin using co-catalysis of hemin/Gquadruplex DNAzyme and octahedral Cu2O-Au nanocomposites for signal amplification. Biosensors & Bioelectronics, 2018, 99: 338–345 https://doi.org/10.1016/j.bios.2017.08.006
27
D Dai, H Liu, H Ma, Z Huang, C Gu, M Zhang. In-situ synthesis of Cu2O-Au nanocomposites as nanozyme for colorimetric determination of hydrogen peroxide. Journal of Alloys and Compounds, 2018, 747: 676–683 https://doi.org/10.1016/j.jallcom.2018.03.054
28
H Luo, J Zhou, H Zhong, L Zhou, Z Jia, X Tan. Polyhedron Cu2O@Ag composite microstructures: Synthesis, mechanism analysis and structure dependent SERS properties. Royal Society of Chemistry Advances, 2016, 6(101): 99105–99113 https://doi.org/10.1039/C6RA20856H
29
S Kandula, P Jeevanandam. Synthesis of Cu2O@Ag polyhedral core–shell nanoparticles by a thermal decomposition approach for catalytic applications. European Journal of Inorganic Chemistry, 2016, 2016(10): 1548–1557 https://doi.org/10.1002/ejic.201501389
30
Y Wang, T Gao, K Wang, X Wu, X Shi, Y Liu, S Lou, S Zhou. Template-assisted synthesis of uniform nanosheet-assembled silver hollow microcubes. Nanoscale, 2012, 4(22): 7121–7126 https://doi.org/10.1039/c2nr32054a
31
M C Biesinger, L W M Lau, A R Gerson, R S C Smart. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn. Applied Surface Science, 2010, 257(3): 887–898 https://doi.org/10.1016/j.apsusc.2010.07.086
32
C W Li, M W Kanan. CO2 reduction at low overpotential on Cu electrodes resulting from the reduction of thick Cu2O films. Journal of the American Chemical Society, 2012, 134(17): 7231–7234 https://doi.org/10.1021/ja3010978
