image: CNTs and Ni-Ni(OH)2 heterostructures were integrated onto a self-supported film by composite deposition and subsequent in-situ oxidation. The synthesized CNTs-Ni-Ni(OH)2 catalyst exhibited rather excellent performance for HER. The improved catalytic activity for HER could be attributed to the enhanced electrochemical active surface area and optimal adsorption strength of H atom. The integrated CNTs and heterostructure could synergistically promote HER by facilitating water adsorption and dissociation as well as accelerating the desorption of Had.
Credit: Chinese Journal of Catalysis
Combining renewable power sources with electrochemical dissociation of water, generated hydrogen could store energy to substitute traditional fossil fuel. Importantly, cost-effective catalysts with high activity for hydrogen evolution reaction (HER) can greatly reduce energy consumption, and therefore are desperately needed, such as Ni-based catalysts. In alkaline electrolyte, HER takes place through the dissociation of adsorbed H2O and the desorption of H2. However, both steps are sluggish on Ni. Fortunately, the restricted procedures can be significantly improved by hybridization with functional components. Ni(OH)2 has been proved to intrinsically accelerate the HO-H bond cleavage, and CNTs may influence the activation energy of catalytic reaction. Therefore, the preparation of Ni-based catalyst integrated with functional CNTs and Ni-Ni(OH)2 heterostructure may provide a distinct strategy for activated HER.
Recently, a research team led by Prof. Gang Wu (University at Buffalo, The State University of New York, United States) & Dr. Dong Tian (University of Jinan, China) designed a self-supported CNTs-Ni-Ni(OH)2 film catalyst with 3D structure for activated HER. CNTs and heterostructure multifunctional components in the synthesized CNTs-Ni-Ni(OH)2 catalyst could synergistically promote HER and lead to excellent performance. The results were published in Chinese Journal of Catalysis (https://doi.org/10.1016/S1872-2067(24)60057-4).
The designed CNTs-Ni-Ni(OH)2 hybrid film could be simply prepared by composite electrodeposition and subsequent in-situ oxidation. The co-deposition of CNTs with Ni generated a 3D CNTs-Ni hybrid film. Additionally, in-situ oxidation treatment in H2O2 could lead to the formation of interfacial Ni-Ni(OH)2 heterostructure. The outstanding catalytic property of synthesized CNTs-Ni-Ni(OH)2 film for HER in alkaline solution could be demonstrated by linear sweep voltammetry as well as chronopotentiometry. CNTs-Ni-Ni(OH)2 catalyst exhibited 0 mV onset overpotential for HER, and overpotentials of 65 mV and 109 mV at 10 mA/cm2 and 50 mA/cm2 respectively. Furthermore, chronopotentiometry identified a low and steady overpotential.
The integration of CNTs as well as Ni-Ni(OH)2 heterostructure were both of great significance. From the point of view of geometrical factors, they both contributed to the enhanced electrochemical active surface area. More importantly, the incorporation of CNTs and heterostructure adjusted the d band center of Ni (ɛd) to an optimal value (-1.179 eV). CNTs and heterostructure synergistically led to the moderate adsorption of H, accelerated HER, and decreased overpotential. Therefore, the designed 3D CNTs-Ni-Ni(OH)2 catalyst showed extraordinary performance for HER, and suggested promising application for HER in alkaline solution.
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About the Journal
Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top one journals in Applied Chemistry with a current SCI impact factor of 15.7. The Editors-in-Chief are Profs. Can Li and Tao Zhang.
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Journal
Chinese Journal of Catalysis
Article Title
Self-supported film catalyst integrated with multifunctional carbon nanotubes and Ni-Ni(OH)2 heterostructure for promoted hydrogen evolution
Article Publication Date
19-Jul-2024