On the characterization of bimodal porous carbon via water adsorption: The role of pore connectivity and temperature
| Autor: | Duong D. Do, Lumeng Liu, Wenmao Zeng, Meng Liu, Shiliang (Johnathan) Tan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Thermal fluctuations chemistry.chemical_element 02 engineering and technology General Chemistry Microporous material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Characterization (materials science) Adsorption chemistry Chemical engineering Molecule General Materials Science Water cluster 0210 nano-technology Mesoporous material Carbon |
| Zdroj: | Carbon. 179:477-485 |
| ISSN: | 0008-6223 |
| DOI: | 10.1016/j.carbon.2021.04.041 |
| Popis: | The behavior of water adsorption on carbonaceous materials is distinct from the simple gases, enabling it as a complementary probe for characterization. Doing so requires a profound understanding of how water adsorbs microscopically. Experimental water isotherms for bimodal micro-mesoporous carbon exhibit a stepwise behavior with two steps for high temperatures and, surprisingly, one step for low temperatures. The two-step behavior and the unusual temperature dependence is worthy of an explanation from microscopic perspective, and to this end we carried out extensive Monte Carlo simulation for water adsorption in a pore model composed of linearly connected micropore and mesopore. Our simulation results show that water molecules could readily fill the micropore section and the prerequisite for the filling of the mesopore section is the existence of a water cluster spanning across the junction between the micropore and the mesopore at 298 K. Temperature is another important factor and stronger thermal fluctuations at higher temperatures facilitate the advancement of the interfaces of adsorbed water thus making filling in mesopore happen even without the formation of the PSC at high temperatures (e.g., 450 K). The findings in this paper offer useful insights on the characterization of bimodal porous carbon via water adsorption. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect