Carbon nanosheets (CNs) were successfully synthesized from nettle stem (NS) which is an inexpensive material with a high carbon content that is abundantly available in nature. CNs were produced using chemical (potassium hydroxide activation and acid exfoliation) and thermal treatments. Sulfuric (H2SO4), phosphoric (H3PO4) and nitric (HNO3) acid solutions were used for exfoliation. CNs exfoliated by H3PO4 have higher specific surface area (789 m2 g−1) compared to CNs exfoliated by H2SO4 (705 m2 g−1) and HNO3 (106 m2 g−1). In this work, NSCNs were found to be a potential candidate for electrode material in electrochemical capacitors. The maximum specific capacitance of the NSCNs exfoliated by H3PO4 is found to be 27.3 F g−1 at a current density of 0.05 A g−1, while the specific capacitance of NSCNs exfoliated by H2SO4 and HNO3 is 9.34 F g−1 and 1.71 F g−1, respectively. Energy density (0.06–0.95 Wh kg−1) and power density (20.9–26.7 W kg−1) of NSCNs are confirmed to be supercapacitor materials and can be applied in energy storage devices.

Extensive research in nanotechnology has allowed us to improve and revolutionize technology and industry. This had led to an interest in the synthesis of other forms of carbon nanomaterial, such as graphene, fibre, carbon nanotubes and particles. Nowadays, a variety of carbon materials is available offering the flexibility to modify carbon properties. Therefore, the manufacture of carbon materials in different shapes is a likely way to take advantage of the morphology and relate it to the properties of the carbon nanomaterial. Stinging nettle is a new material to study for the production of carbon nanostructured materials. In this research, carbon nanosheets were successfully prepared from stinging nettle (nettle stem and leaf) using potassium hydroxide (KOH), sulphuric acid (H2SO4) and thermal treatment. This method is simple for producing carbon nanosheets from natural materials. Treating the nettle stem with KOH (solid) produces carbon nanosheets with a thickness of ∼159.2– 252.3 nm, while KOH (solute) treatment led to thinner nanosheets (∼70.43–111.2 nm). SEM micrographs of the nettle leaf with KOH (solute) activation show a smooth surface and clearly reveal the formation of carbon nanosheets. However, in the samples activated by KOH (solute) a greater number of micropores were found on the wall. The microstructure and morphology of the samples were investigated by scanning electron microscopy (SEM), the chemical composition was analysed by energy-dispersive X-ray spectrometry (EDS).

In this research, alumina-zeolite composite materials were synthesised by mechanical activation and oxidation sintering technique. A comprehensive examination of the microstructure of the starting raw materials and the sintered ceramic specimens have been studied via X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, several properties were investigated such as volume shrinkage, density, porosity, weight loss and water absorption based on the compositions of the composite specimens, sintering temperature, and microstructure. The authors have found that the raw material compositions and the sintering temperature have great influence in the microstructure and the characteristic of the final prepared ceramic specimens.

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Aluminum scraps are derived from industrial waste in the machining process called turning and are rarely reused. Recycling this wasted aluminum is particularly appealing. The Aluminum powder is made from this industrial waste. This article uses a metallurgical technique to prepare and use scrap recycled aluminum. In this study, the goal was to improve the properties of aluminum scraps by adding graphite powder. This study is based on a powder metallurgical process, where aluminum scraps from the machining processes are converted into fine powder (~60 μm) using a ball mill process. The powder is then mixed into a composite of aluminum powder (Al) and graphite powder (GP) using a high-speed mixing method. The GP added to the Al has a particle matter ratio of 0.25, 0.5, 0.75, and 1.0 percent by weight. The composite powder is then compressed into a test specimen and sent for sintering. The study aims to look at the mechanical and electrical properties after the introduction of graphite powder. In ideal circumstances, the study showed an increase in ultimate tensile strength (UTS), young’s modulus (E), hardness, and electrical conductivity of composite in comparison with pure aluminum, with a UTS value of 140.32 MPa up from 131.05 MPa, an E value of 49.78 GPa up from 41.48 GPa and a hardness value of 91.88 HV up from 64.69 HV.