Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry
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2020
Authors
Rajić, Vladimir
Stojković Simatović, Ivana

Veselinović, Ljiljana

Belošević Čavor, Jelena

Novaković, Mirjana

Popović, Maja

Škapin, Srečo Davor

Mojović, Miloš

Stojadinović, Stevan

Rac, Vladislav

Janković Častvan, Ivona

Marković, Smilja

Article (Published version)

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Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient a...mount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.
Source:
Physical Chemistry Chemical Physics, 2020, 22, 38, 22078-22095Publisher:
- Royal Society of Chemistry
Funding / projects:
- Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 200175 (Institute of Technical Sciences of SASA, Belgrade) (RS-200175)
- Ministry of Education, Science and Technological Development, Republic of Serbia, Grant no. 200017 (University of Belgrade, Institute of Nuclear Sciences 'Vinča', Belgrade-Vinča) (RS-200017)
- Bilateral cooperation program between the Republic of Serbia and the Republic of Slovenia “Nanostructured and mesoporous functional materials with enhanced solar light driven photocatalytic activity” for 2018–2019
Note:
- Peer-reviewed manuscript: https://hdl.handle.net/21.15107/rcub_dais_9544
Related info:
DOI: 10.1039/D0CP03377D
ISBN: 1463-9084
WoS: 000576194400046
Scopus: 2-s2.0-85092681262
URI
https://pubs.rsc.org/en/content/articlelanding/2020/cp/d0cp03377dhttps://dais.sanu.ac.rs/123456789/9543
Institution/Community
Институт техничких наука САНУ / Institute of Technical Sciences of SASATY - JOUR AU - Rajić, Vladimir AU - Stojković Simatović, Ivana AU - Veselinović, Ljiljana AU - Belošević Čavor, Jelena AU - Novaković, Mirjana AU - Popović, Maja AU - Škapin, Srečo Davor AU - Mojović, Miloš AU - Stojadinović, Stevan AU - Rac, Vladislav AU - Janković Častvan, Ivona AU - Marković, Smilja PY - 2020 UR - https://pubs.rsc.org/en/content/articlelanding/2020/cp/d0cp03377d UR - https://dais.sanu.ac.rs/123456789/9543 AB - Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO. PB - Royal Society of Chemistry T2 - Physical Chemistry Chemical Physics T1 - Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry SP - 22078 EP - 22095 VL - 22 IS - 38 DO - 10.1039/D0CP03377D UR - https://hdl.handle.net/21.15107/rcub_dais_9543 ER -
@article{ author = "Rajić, Vladimir and Stojković Simatović, Ivana and Veselinović, Ljiljana and Belošević Čavor, Jelena and Novaković, Mirjana and Popović, Maja and Škapin, Srečo Davor and Mojović, Miloš and Stojadinović, Stevan and Rac, Vladislav and Janković Častvan, Ivona and Marković, Smilja", year = "2020", abstract = "Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.", publisher = "Royal Society of Chemistry", journal = "Physical Chemistry Chemical Physics", title = "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry", pages = "22078-22095", volume = "22", number = "38", doi = "10.1039/D0CP03377D", url = "https://hdl.handle.net/21.15107/rcub_dais_9543" }
Rajić, V., Stojković Simatović, I., Veselinović, L., Belošević Čavor, J., Novaković, M., Popović, M., Škapin, S. D., Mojović, M., Stojadinović, S., Rac, V., Janković Častvan, I.,& Marković, S.. (2020). Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry. in Physical Chemistry Chemical Physics Royal Society of Chemistry., 22(38), 22078-22095. https://doi.org/10.1039/D0CP03377D https://hdl.handle.net/21.15107/rcub_dais_9543
Rajić V, Stojković Simatović I, Veselinović L, Belošević Čavor J, Novaković M, Popović M, Škapin SD, Mojović M, Stojadinović S, Rac V, Janković Častvan I, Marković S. Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry. in Physical Chemistry Chemical Physics. 2020;22(38):22078-22095. doi:10.1039/D0CP03377D https://hdl.handle.net/21.15107/rcub_dais_9543 .
Rajić, Vladimir, Stojković Simatović, Ivana, Veselinović, Ljiljana, Belošević Čavor, Jelena, Novaković, Mirjana, Popović, Maja, Škapin, Srečo Davor, Mojović, Miloš, Stojadinović, Stevan, Rac, Vladislav, Janković Častvan, Ivona, Marković, Smilja, "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry" in Physical Chemistry Chemical Physics, 22, no. 38 (2020):22078-22095, https://doi.org/10.1039/D0CP03377D ., https://hdl.handle.net/21.15107/rcub_dais_9543 .