Identification of Semiconductive Patches in Thermally Processed Monolayer Oxo‐Functionalized Graphene

Abstract

The thermal decomposition of graphene oxide (GO) is a complex process at the atomic level and not fully understood. Here, a subclass of GO, oxo-functionalized graphene (oxo-G), was used to study its thermal disproportionation. We present the impact of annealing on the electronic properties of a monolayer oxo-G flake and correlated the chemical composition and topography corrugation by twoprobe transport measurements, XPS, TEM, FTIR and STM. Surprisingly, we found that oxo-G, processed at 300 8C, displays CÀC sp 3-patches and possibly CÀOÀC bonds, next to graphene domains and holes. It is striking that those CÀOÀ C/C À C sp 3-separated sp 2-patches a few nanometers in diameter possess semiconducting properties with a band gap of about 0.4 eV. We propose that sp 3-patches confine conjugated sp 2-C atoms, which leads to the local semiconductor properties. Accordingly, graphene with sp 3-C in double layer areas is a potential class of semiconductors and a potential target for future chemical modifications.

A High-Performance Zinc-Organic Framework with Accessible Open Metal Sites Catalyzes CO2 and Styrene Oxide into Styrene Carbonate under Mild Conditions

“…Additionally, the O 1s XPS peaks in Figure c located at 531.0, 531.8, and 532.7 eV are related to Zn–O, C–O, and CO bonds. , The analysis results of carbon environments are also presented in Figure d. These spectra can be deconvoluted into five components at 284.0, 284.6, 285.2, 286.0, and 288.7 eV, which are assigned to abundant CC, C–C, C–N, C–O, and CO/CN bonds, respectively. − …”

Synthesis of Wet‐Chemically Prepared Porous‐Graphene Single Layers on Si/SiO2 Substrate Increasing the Photoluminescence of MoS2 in Heterostructures

“…The oxygen content is significantly reduced in comparison to oxoG and close to zero if we consider its influence on SiO 2 . [2,44,45] We note, for analyzing the CO species the C 1s analysis is representative. The analyses of C 1s peaks reveal the formation of CO and CO/COH groups as a consequence of annealing and the accompanied growth of pores (Figure 4B).…”

“…Graphene with defects, such as pores in the lattice of graphene [1][2][3] finds emerging applications for water separation, gas separation and purification, or sensing. [4][5][6][7][8][9][10] The chemical functionalization of graphene can either be accomplished with graphene dispersed in solvents, [11] or with graphene deposited on surfaces.…”

Graphene Oxide for Integrated Photonics and Flat Optics

“…Hence, GO can potentially be both reduced and oxidized at the same time, which would generate excess defects. [54,55] Chemical methods have a strong capability for removing OFGs, while they are not particularly compatible with on-chip integration as well as film patterning and so are not the focus of this article. By contrast, photoreduction does not involve high temperatures or toxic chemicals and offers unique advantages due to its moderate reaction conditions, exquisite control over the degree of reduction, and capability of advanced patterning designs.…”