Deepening the Understanding of Carbon Active Sites for ORR Using Electrochemical and Spectrochemical Techniques
Abstract
:1. Introduction
2. Experimental
2.1. Materials and Reagents
2.2. Purification and Thermal Treatment of the MWCNTs
2.3. Physicochemical Characterization
2.4. Carbon-Oxygen Gasification Characterization
2.5. Electrochemical Characterization
3. Results and Discussion
3.1. TEM Analysis of the Materials
3.2. Characterization of the Surface Chemistry and Bulk Composition
3.3. Porous Texture and Carbon-Oxygen Gasification Properties
3.4. RAMAN Spectroscopy
3.5. Electrochemical Characterization
3.6. Electrocatalytic Activity for ORR
4. Importance of Surface Chemical Analysis and Electrochemical and Spectrochemical Results in the ORR Performance
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Samples | XPS | EDX | Elemental Analysis | |||||
---|---|---|---|---|---|---|---|---|
C wt% | O wt% | N wt% | C wt% | O wt% | Other Elements wt% | C wt% | H wt% | |
MW99_P | 98.1 | 1.8 | 0.1 | 97.6 | 1.3 | 1.1 * | 99.3 | 0.0 |
MW99_T | 98.7 | 1.3 | 0.0 | 100.0 | 0.0 | 0.0 | 99.9 | 0.1 |
MW95_P | 97.8 | 1.4 | 0.8 | 95.6 | 1.6 | 2.8 ** | 89.5 | 0.0 |
MW95_T | 98.8 | 1.2 | 0.0 | 97.6 | 0.9 | 1.5 ** | 96.7 | 0.1 |
Samples | CO/µmol g−1 | CO2/µmol g−1 | O/µmol g−1 | BET Surface Area/m2 g−1 | ASA/m2 g−1 | R550/g g−1 h−1 |
---|---|---|---|---|---|---|
MW99_P | 1370 | 105 | 1580 | 195 | 2.35 | 8.1 |
MW99_T | 389 | 59 | 507 | 307 | 9.37 | 1.4 |
MW95_P | 2220 | 217 | 2654 | 253 | 38.2 | 4.6 |
MW95_T | 985 | 117 | 1219 | 465 | 13.1 | 5.8 |
Samples | Bandwidth D + D′/cm−1 | ID/IG | ID/ID′ | I2D/ID | Lsp2/nm | LD/nm | nD × 1011/cm−2 |
---|---|---|---|---|---|---|---|
MW99_P | 120 | 1.42 | 3.23 | 0.35 | 13.35 | 11.63 | 4.26 |
MW99_T | 106 | 1.94 | 3.61 | 0.23 | 9.78 | 9.95 | 5.81 |
MW95_P | 83 | 0.29 | - | 0.97 | 66.43 | 25.94 | 0.86 |
MW95_T | 100 | 0.49 | - | 0.45 | 38.45 | 19.74 | 1.48 |
Sample | k0/cm s−1 | EASA/ m2 g−1 | /V (at −0.10 mA/cm2) | /V | (at 0.7 V) | /mA cm−2 (at 0.4 V) | Tafel Slope/mV dec−1 |
---|---|---|---|---|---|---|---|
MW99_P | 1.44 × 10−3 | 4.50 | 0.80 | 0.66 | 2.97 | −5.11 | 61 |
MW99_T | 1.82 × 10−3 | 9.07 | 0.85 | 0.73 | 3.35 | −7.52 | 39 |
MW95_P | 2.11 × 10−3 | 9.07 | 0.82 | 0.70 | 2.80 | −3.53 | 58 |
MW95_T | 2.32 × 10−3 | 11.43 | 0.84 | 0.76 | 2.97 | −3.67 | 47 |
Pt/C | - | - | 0.98 | 0.86 | 3.99 | −5.51 | 60 |
Sample | kº/cm s−1 | EASA/m2 g−1 | jk/A g−1 | ASA/m2 g−1 | R550/g g−1 h−1 | nD × 1011/cm−2 |
---|---|---|---|---|---|---|
XC72 | 1.82 × 10−3 | 5.58 [33] | 5.21 | 4.7 [33] | 0.7 [33] | 4.49 |
AC | 1.06 × 10−3 | 7.51 [33] | 7.69 | 36.7 [33] | 2.2 [33] | 4.42 |
YPF | 1.20 × 10−3 | 10.97 [33] | 6.69 | 26.4 [33] | 2.2 [33] | 4.31 |
CNF | 1.34 × 10−3 | 6.49 [33] | 6.44 | 28.9 [33] | 2.0 [33] | 5.34 |
Herring | 8.29 × 10−3 | 4.04 [33] | 5.71 | 2.2 [33] | 0.5 [33] | 2.50 |
SW | 8.29 × 10−3 | 6.89 [33] | 8.50 | 6.1 [33] | 2.4 [33] | 1.99 |
MW95_T | 2.32 × 10−3 | 11.45 | 6.32 | 13.1 | 5.8 | 1.48 |
MW99_T | 1.82 × 10−3 | 9.07 | 9.27 | 9.37 | 1.4 | 5.81 |
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Flores-Lasluisa, J.X.; Cazorla-Amorós, D.; Morallón, E. Deepening the Understanding of Carbon Active Sites for ORR Using Electrochemical and Spectrochemical Techniques. Nanomaterials 2024, 14, 1381. https://doi.org/10.3390/nano14171381
Flores-Lasluisa JX, Cazorla-Amorós D, Morallón E. Deepening the Understanding of Carbon Active Sites for ORR Using Electrochemical and Spectrochemical Techniques. Nanomaterials. 2024; 14(17):1381. https://doi.org/10.3390/nano14171381
Chicago/Turabian StyleFlores-Lasluisa, Jhony Xavier, Diego Cazorla-Amorós, and Emilia Morallón. 2024. "Deepening the Understanding of Carbon Active Sites for ORR Using Electrochemical and Spectrochemical Techniques" Nanomaterials 14, no. 17: 1381. https://doi.org/10.3390/nano14171381