Engaging nanoporous carbons in “beyond adsorption” applications: Characterization, challenges and performance

Abstract

This paper addresses the challenges of explaining the behavior of porous carbons in cutting-edge applications related to energy storage, catalysis, photocatalysis, and advanced separation based on reactive adsorption. It is a summary of the outcomes of the extensive discussion which took place during the workshop "Beyond Adsorption-II: new perspectives and challenges for nanoporous carbons," organized as a satellite event to the International Carbon Conference on July 20 th 2019 in New York. It is not our intention to provide a tutorial on the applications, characterization or performance testing of porous carbons; we would rather like to focus on the controversy of the results and phenomena, on the explanation of findings, and on raising concerns to the growing carbon-researching scientific community about the importance of understanding the features of nanoporous carbons by choosing an appropriate characterization 2 technique that will bring meaningful information. We want to emphasize that nanoporous carbons have unique features ensuring them making a marked advance in science and technology. Even though recent studies have shown their potential in various emerging applications, the origin of such performance is not yet well understood. Thus, scientists are encouraged to focus on a precise characterization of porous carbons using a set of complementary techniques for triggering future technological developments.

Solid-phase extraction cartridges with multi-walled carbon nanotubes and effect of the oxygen functionalities on the recovery efficiency of organic micropollutants

“…This methodology allows the fine control of the type and amount of surface groups introduced on carbon materials by adjusting the concentration of oxidizing agent employed in the treatment (HNO 3 concentration in the range 0.01-0.30 mol L −1 ), as determined by different characterization techniques. This distinctive feature allowed establishing correlations between both the synthesis conditions and the oxygen-containing surface functionalities introduced on the MWCNTs; and the type and amount of those functionalities and the recoveries obtained for the 8 target OMPs; while employing much lower concentrations of oxidizing agent than those previously reported with similar hydrothermal methodologies [23][24][25][26] . Therefore, the novelty of this study relies on (i) the development of a systematic study, upon application of a controlled HNO 3 hydrothermal oxidation methodology to pristine MWCNTs; but also on (ii) the use of ethanol as elution solvent in the SPE procedure, when using MWCNT cartridges; and (iii) the study of metaflumizone for the first time in real water compartments.…”

“…Briefly, TPD is a well-established advanced characterization technique assuming that all oxygen-containing surface groups are decomposed into CO 2 and CO upon heating under controlled operating conditions 28 . In this case, a low heating rate of 10° C min −1 , and a high helium flow of 25 cm 3 min −1 were set to minimize secondary reactions during the experiments 26 , 28 . The mass signals m/z = 28 and 44 were monitored during the thermal analysis, the corresponding TPD spectra being obtained.…”

Link between Alkali Metals in Salt Templates and in Electrolytes for Improved Carbon-Based Electrochemical Capacitors

“… 31 Finally, one must keep in mind that an estimation of the specific surface area based on adsorption techniques might come with some limitations, and particular attention should be paid to the data interpretation and correlation. 9 , 32 − 34 …”

Hierarchical Doped Gelatin-Derived Carbon Aerogels: Three Levels of Porosity for Advanced Supercapacitors

“…Hence, when activated at 800 °C, the aerogel had a greater specific area than that activated at either 700 °C and 900 °C. It should be noted that the choice of appropriate characterization techniques and testing parameters is critical in obtaining data that accurately account for the behavior of these complex structures [ 41 ].…”