Functional carbon nanosheets prepared from hexayne amphiphile monolayers at room temperature

Abstract

Carbon nanostructures that feature two-dimensional extended nanosheets are important components for technological applications such as high-performance composites, lithium-ion storage, photovoltaics and nanoelectronics. Chemical functionalization would render such structures better processable and more suited for tailored applications, but typically this is precluded by the high temperatures needed to prepare the nanosheets. Here, we report direct access to functional carbon nanosheets of uniform thickness at room temperature. We used amphiphiles that contain hexayne segments as metastable carbon precursors and self-assembled these into ordered monolayers at the air/water interface. Subsequent carbonization by ultraviolet irradiation in ambient conditions resulted in the quantitative carbonization of the hexayne sublayer. Carbon nanosheets prepared in this way retained their surface functionalization and featured an sp(2)-rich amorphous carbon structure comparable to that usually obtained on annealing above 800 °C. Moreover, they exhibited a molecularly defined thickness of 1.9 nm, were mechanically self-supporting over several micrometres and had macroscopic lateral dimensions on the order of centimetres.

Design Considerations for Unconventional Electrochemical Energy Storage Architectures

“…Mild chemistries for carbon nanosheets growth have been recently proposed and although this can be realized even at room temperature, defect free application of such versatile coatings remains the subject of further developments. [ 596 ] Graphene has been also used as an encapsulation material for lithium-sulfur (Li-S) batteries. [ 597 ] Li-S (alongside with Li-O 2 ) battery is considered as one of the future energy storage systems given the very high specifi c energy and energy density it can provide: 2567 Wh/kg and 2199 Wh l −1 , respectively.…”

Preparation of Carbon Nanosheets at Room Temperature

“…The desired hexayne amphiphile (3) is straightforwardly prepared by the sequential bromination 52,53 and Pd-catalyzed elongation 30,31 of the alkyne segment, followed by a final deprotection reaction of the tritylphenyl ester (2) (Figure 1a) 29 . The successful synthesis is confirmed by the 13 C NMR spectrum (Figure 1b) as well as the UV-Vis absorption spectrum (Figure 1c) 31,54 .…”

“…The above mentioned limitations have been addressed in our group by employing highly reactive oligoynes that can be converted into carbon nanomaterials at room temperature 28,29 . In particular, amphiphiles comprising a hydrophilic head group and a hexayne segment are accessible through a sequence of bromination and palladium-mediated Negishi cross-coupling reactions 30,31 .…”

A Functional Group Approach for Prediction of APPI Response of Organic Synthetic Targets

“…However, this is of particular interest to researchers in areas such as supramolecular chemistry [71,72], drug delivery via nanomaterials [73,74], solar cells development [75][76][77], or vaccine adjuvants [78,79], as oftentimes compounds of interest lack basic/acidic sites, may be non-polar, and do not ionize well with ESI. Here, a selection of such analytes investigated in our institute is given, compiled from recently published research articles [35,37,[80][81][82][83]. Notably, APPI was able to ionize analytes near or above 3 kDa, with several selected complexes showcasing the variation in underlying chemical diversity demonstrated in compounds A-H, which also include metal complexes (see Figure 5 for compound structure and Supplementary Figure S2 for associated APPI mass spectra).…”