## 1 Introduction  
Over the years, alongside classical carbon forms like the hardest and electrically insulating diamond and the softest and electrically conducting graphite, various novel carbon allotropes have been progressively discovered and developed, forming a new family of carbon materials. This family includes zero-dimensional fullerenes and carbon dots, one-dimensional carbon nanotubes and carbon fibers, and two-dimensional graphene, and graphyne, along with their derivatives [1, 2]. Impressively, these carbon materials showcase numerous distinctive properties, such as a large specific surface area, tunable porosity, chemical surface functionality, exceptional thermal and electrical conductivity, mechanical and chemical stability, and diverse structures, rendering them highly promising materials for future applications [3, 4]. While carbon nanomaterials hold great promise for various applications, the cost-effective and environmentally friendly production of these materials poses a considerable challenge. Traditional manufacturing methods for graphene, carbon nanotubes, and other nanostructured carbon materials frequently rely on expensive carbon precursors and resource-intensive processes [5; 6]. Consequently, the commercial viability and widespread application of carbon materials are impeded by elevated production costs. Therefore, careful consideration must be given to the choice of carbon precursors and synthesis methods in the context of fabricating nanostructured carbon materials. Coal, a fossil fuel originating from the remnants of ancient plants subjected to high pressure and temperature within the Earth's crust, undergoes a series of transformations over millions of years to give rise to the coal deposits found today. Acknowledged for its high energy density, ease of storage, and cost-effectiveness, carbonaceous coal stands as a fundamental and economically viable energy source. Characterized as a naturally occurring heterogeneous macromolecular material, coal possesses a three-dimensional cross-linked architecture. The organic macromolecules within coal consist of a specific number of alicyclic and aromatic/hydroaromatic nuclei connected by short aliphatic and ether linkages [7; 8; 9; 10; 11]. Currently, within the electric industry, the stability of cycles in coke or hard carbon as an anode has been well documented, while graphite electrodes showcase high energy density and exceptional capacity. The exploration of synthesizing soft and environmentally friendly carbon materials, such as nanocarbon derived from coal and coke, stands as a promising research avenue. This is attributed to its potential to yield high-quality materials at a low cost, along with advantages like environmental friendliness, mild processing conditions, and scalability [12; 13; 14; 15]. Several methods have been applied, depending on the desired properties of the final nanocarbon products. [PERSON] et al. [16] synthesized graphene and graphene-based metal materials from coal by using catalytic graphitization, chemical oxidation, and oxygen-reduction-assisted plasma dielectric barrier discharge (DBD). This method converts carbon atoms into a more graphitic form with increased strength and conductivity. Another method known as chemical oxidation was used by [PERSON] et al. [17] to synthesize oxidized graphene from graphite (HOG) with H\({}_{2}\)SO\({}_{4}\) and HNO\({}_{3}\) as the first oxidizing agents and KMnO\({}_{4}\) as the last oxidizing agent. This process occurred within 3.5 h, producing oxygen-containing functional groups on the surface of the carbon. The as-synthesized HOG was more hydrophilic and dispersed easily in aqueous solutions, and it was more oxidized than GO prepared using the Hummers method. [PERSON] [18] successfully fabricated the positive electrode in a Li-ion battery from coke activated by HF and HCl and then calcined at 600 \({}^{\circ}\)C and 900 \({}^{\circ}\)C for 1 h. [PERSON] et al.