Conclusions
In summary, we have demonstrated surface microenvironment optimization as an effective way to design highly active ORR catalyst, serving as air electrode for neutral ZABs. Benefiting from the optimal surface microenvironment induced synergistic effects between different active sites, the achieved Pt-SMO-Co2N NWs presented extraordinary ORR activity. In 2.0 M PBS (pH=7.0), Pt-SMO-Co2N NWs showed a positive onset potential of 0.960V and a half-wave potential of 0.812 V, which is 92mV higher than that of commercial Pt/C. The power density of neutral ZABs taking Pt-SMO-Co2N NWs as cathode catalyst could reach 67.9 mW*cm−2, outperforming commercial Pt/C under the same circumstance and displayed barely decay after 80 hours’ discharge-charge test. Moreover, based on the ideal material platform built on Pt-SMO-Co2N NWs, in-depth characterization and mechanistic understanding of ORR was disclosed. Our work reveals a new strategy for the ORR catalyst design through the construction of optimal surface microenvironment and offers new insights toward the key role of activating H2O and facilitating proton transfer process in ORR catalysis.
ASSOCIATED CONTENT
XRD patterns, TEM images and additional electrochemical date are included in the supporting information. This material is available free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
czwu@ustc.edu.cn;
yxie@ustxc.edu.cn
Author Contributions
§These authors contributed equally.
Notes The authors declare no competing financial interests.
ACKNOWLEDGMENT
This work was financially supported by the National Basic Research Program of China (2017YFA0206702), Natural Science Foundation of China (No. 21925110, 21890751), China Postdoctoral Science Foundation (2019TQ0299) and Fundamental Research Funds for the Central Universities (No. WK 2060190084, No. WK 5290000001). The authors thank Dr Jie Tian and Dr Huijuan Wang at Engineering and Materials Science Experiment Centre for the help of HRTEM experiments. The authors also appreciate the support from the Major/Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology. This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
REFERENCES
1. Larcher, D. & Tarascon, J. M. Towards greener and more sustainable batteries for electrical energy storage. Nat. Chem. 7 , 19-29, doi:10.1038/nchem.2085 (2015).
2. Aricò, A. S., Bruce, P., Scrosati, B., Tarascon, J.-M. & van Schalkwijk, W. Nanostructured materials for advanced energy conversion and storage devices. Nat. Mater. 4 , 366-377, doi:10.1038/nmat1368 (2005).
3. Dresselhaus, M. S. & Thomas, I. L. Alternative energy technologies.Nature 414 , 332-337, doi:10.1038/35104599 (2001).
4. Suntivich, J. et al. Design principles for oxygen-reduction activity on perovskite oxide catalysts for fuel cells and metal–air batteries.Nat. Chem. 3 , 546-550, doi:10.1038/nchem.1069 (2011).
5. Debe, M. K. Electrocatalyst approaches and challenges for automotive fuel cells. Nature 486 , 43-51, doi:10.1038/nature11115 (2012).
6. Tang, C., Wang, B., Wang, H.-F. & Zhang, Q. Defect engineering toward atomic Co–Nx–C in hierarchical graphene for rechargeable flexible solid Zn-air batteries. Adv. Mater. 29 , 1703185, doi:10.1002/adma.201703185 (2017).
7. Yu, P. et al. Co Nanoislands rooted on Co–N–C nanosheets as efficient oxygen electrocatalyst for Zn–air batteries. Adv. Mater. 31 , 1901666, doi:10.1002/adma.201901666 (2019).
8. Meng, F., Zhong, H., Bao, D., Yan, J. & Zhang, X. In situ coupling of strung Co4N and intertwined N–C fibers toward free-standing bifunctional cathode for robust, efficient, and flexible Zn–air batteries. J. Am. Chem. Soc. 138 , 10226-10231, doi:10.1021/jacs.6b05046 (2016).
9. Jiang, Y. et al. Interpenetrating triphase cobalt-based nanocomposites as efficient bifunctional oxygen electrocatalysts for long-lasting rechargeable Zn–air batteries. Adv. Energy. Mater.8 , 1702900, doi:10.1002/aenm.201702900 (2018).
10. Tong, Y. et al. A bifunctional hybrid electrocatalyst for oxygen reduction and evolution: cobalt oxide nanoparticles strongly coupled to B, N-decorated graphene. Angew. Chem. Int. Ed.56 , 7121-7125, doi:10.1002/anie.201702430 (2017).
11. Li, Y. & Dai, H. Recent advances in zinc–air batteries.Chem. Soc. Rev. 43 , 5257-5275, doi:10.1039/C4CS00015C (2014).
12. Xia, B. Y. et al. A metal–organic framework-derived bifunctional oxygen electrocatalyst. Nat. Energy. 1 , 15006, doi:10.1038/nenergy.2015.6 (2016).
13. Sumboja, A. et al. Durable rechargeable zinc-air batteries with neutral electrolyte and manganese oxide catalyst. J. Power Sources. 332 , 330-336, doi:10.1016/j.jpowsour.2016.09.142 (2016).
14. Su, Y. et al. A highly efficient catalyst toward oxygen reduction reaction in neutral media for microbial fuel cells. Ind. Eng. Chem. Res. 52 , 6076-6082, doi:10.1021/ie4003766 (2013).
15. Clark, S., Latz, A. & Horstmann, B. Rational development of neutral aqueous electrolytes for zinc-air batteries. ChemSusChem.10 , 4735-4747, doi:10.1002/cssc.201701468 (2017).
16. Xie, L. et al. Molecular engineering of a 3D self-supported electrode for oxygen electrocatalysis in neutral media. Angew. Chem. Int. Ed. 58 , 18883-18887, doi:10.1002/anie.201911441 (2019).
17. Jung, J.-I., Jeong, H. Y., Lee, J.-S., Kim, M. G. & Cho, J. A bifunctional perovskite catalyst for oxygen reduction and evolution.Angew. Chem. Int. Ed. 53 , 4582-4586, doi:10.1002/anie.201311223 (2014).
18. Ma, T. Y., Ran, J., Dai, S., Jaroniec, M. & Qiao, S. Z. Phosphorus-Doped Graphitic Carbon Nitrides Grown In Situ on Carbon-Fiber Paper: Flexible and Reversible Oxygen Electrodes. Angew. Chem. Int. Ed. 54 , 4646-4650, doi:10.1002/anie.201411125 (2015).
19. Gong, M. et al. Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis.Nat. Commun. 5 , 4695, doi:10.1038/ncomms5695 (2014).
20. Lu, X. F., Chen, Y., Wang, S., Gao, S. & Lou, X. W. Interfacing manganese oxide and cobalt in porous graphitic carbon polyhedrons boosts oxygen electrocatalysis for Zn–air batteries. Adv. Mater.31 , 1902339, doi:10.1002/adma.201902339 (2019).
21.Xing, Z., Hu, L., Ripatti, D. S., Hu, X. & Feng, X. Enhancing carbon dioxide gas-diffusion electrolysis by creating a hydrophobic catalyst microenvironment. Nat. Commun. 12 , 136, doi:10.1038/s41467-020-20397-5 (2021).
22. Guo, C. et al. Engineering High-Energy Interfacial Structures for High-Performance Oxygen-Involving Electrocatalysis. Angew. Chem. Int. Ed. 56 , 8539-8543, doi:10.1002/anie.201701531 (2017).
23. Yu, L., Yi, Q., Li, G., Chen, Y. & Yang, X. FeCo-Doped Hollow Bamboo-Like C-N Composites as Cathodic Catalysts for Zinc-Air Battery in Neutral Media. J. Electrochem. Soc 165 , A2502-A2509, doi:10.1149/2.0481811jes (2018).
24. Shao, M., Chang, Q., Dodelet, J.-P. & Chenitz, R. Recent Advances in Electrocatalysts for Oxygen Reduction Reaction. Chem. Rev.116 , 3594-3657, doi:10.1021/acs.chemrev.5b00462 (2016).
25. Jin, H. et al. In situ Cobalt–Cobalt Oxide/N-Doped Carbon Hybrids As Superior Bifunctional Electrocatalysts for Hydrogen and Oxygen Evolution. J. Am. Chem. Soc. 137 , 2688-2694, doi:10.1021/ja5127165 (2015).
26. Liu, S. et al. Dual Modulation via Electrochemical Reduction Activiation on Electrocatalysts for Enhanced Oxygen Evolution Reaction.ACS Energy Lett. 4 , 423-429, doi:10.1021/acsenergylett.8b01974 (2019).
27. Kerrec, O., Devilliers, D., Groult, H. & Marcus, P. Study of dry and electrogenerated Ta2O5 and Ta/Ta2O5/Pt structures by XPS.Mater. Sci. Eng. B. 55 , 134-142, doi:https://doi.org/10.1016/S0921-5107(98)00177-9 (1998).
28. Chen, Y. et al. Atomic-Level Modulation of Electronic Density at Cobalt Single-Atom Sites Derived from Metal–Organic Frameworks: Enhanced Oxygen Reduction Performance. Angew. Chem. Int. Ed. doi: 10.1002/anie.202012798.
29. Zhou, T. et al. Ultrathin Cobalt Oxide Layers as Electrocatalysts for High-Performance Flexible Zn–Air Batteries.Adv. Mater. 31 , 1807468, doi:10.1002/adma.201807468 (2019).
30. Wang, Y. et al. Synergistic Mn-Co catalyst outperforms Pt on high-rate oxygen reduction for alkaline polymer electrolyte fuel cells.Nat. Commun. 10 , 1506, doi:10.1038/s41467-019-09503-4 (2019).
31. Subbaraman, R. et al. Trends in activity for the water electrolyser reactions on 3d M(Ni,Co,Fe,Mn) hydr(oxy)oxide catalysts.Nat. Mater. 11 , 550-557, doi:10.1038/nmat3313 (2012).
32. Xu, K. et al. Controllable Surface Reorganization Engineering on Cobalt Phosphide Nanowire Arrays for Efficient Alkaline Hydrogen Evolution Reaction. Adv. Mater. 30 , 1703322, doi:10.1002/adma.201703322 (2018).