Formation of onion-like fullerene and chemically converted graphene-like nanosheets from low-quality coals: application in photocatalytic degradation of 2-nitrophenol

Abstract

The formation of onion-like fullerene and chemically converted graphene-like nanosheets from low-quality coals were observed during an oxidation-cum-extraction (OCE) process.

Review of Graphene Supercapacitors and Different Modified Graphene Electrodes

“…In their research, coal is first oxidized by nitric acid, and then extracted in an alkaline solution of sodium hydroxide. During oxidative extraction, they observed the formation of coal derived carbon nanomaterials and some clusters of graphene nanoflakes [14]. In 2017, He team proposed a completely new synthesis method using nano ZnO template strategy and combined with KOH in situ activation technology to prepare 3D interconnected graphene nanocapsules from a variety of aromatic hydrocarbons.…”

Nanodiamonds Produced from Low-Grade Indian Coals

“…50−55 In some of the previous studies, the formation of carbon nanotubes, nanoballs, 56 onion-like fullerenes, and chemically converted graphene-like carbon nanosheets from Northeast Indian lowgrade coal has been reported. 49 The Northeast region (NER) of India has around 1.496 Gt of low-grade coal reserves. These tertiary coals have high-sulfur contents (2−8%), where 75−90% is organically bound, while the rest is in inorganic forms viz.…”

“…sulfate sulfur and pyritic sulfur. 49,56,57 Thus, the NER coals need beneficiation as well as value addition for further gainful utilization.…”

Mesoporous onion-like carbon nanostructures from natural oil for high-performance supercapacitor and electrochemical sensing applications: Insights into the post-synthesis sonochemical treatment on the electrochemical performance

“…In both the samples, the prominent peak at ∼284.5 eV is attributed to graphitic sp 2 carbon, and the peak at ∼285.4 eV corresponds to disordered sp 3 carbon fraction in the OLCs. The peaks at ∼286.5 eV and ∼288.8 eV are attributed to oxygen functionalities, namely C–O (such as hydroxyl, phenol, epoxide) and C O (such as carbonyl, carboxyl) [36] . An appreciable decrease in the sp 2 carbon and increase in the sp 3 carbon component is witnessed, revealed by the decrease in the Csp 2 /Csp 3 ratio from 5.1 in as-prepared OLCs to 2.6 in sonicated OLCs, confirming the increase in defects generated by ultrasonication treatment.…”