Fabrication of Nano-Onion-Structured Graphene Films from Citrus sinensis Extract and Their Wetting and Sensing Characteristics

Abstract

Graphene and its derivatives have acquired substantial research attention in recent years because of their wide range of potential applications. Implementing sustainable technologies for fabricating these functional nanomaterials is becoming increasingly apparent, and therefore, a wide spectrum of naturally derived precursors has been identified and reformed through various established techniques for the purpose. Nevertheless, most of these methods could only be considered partially sustainable because of their complexity as well as high energy, time, and resource requirements. Here, we report the fabrication of carbon nano-onion-interspersed vertically oriented multilayer graphene nanosheets through a single-step, environmentally benign radio frequency plasma-enhanced chemical vapor deposition process from a low-cost carbon feedstock, the oil from the peel of Citrus sinensis orange fruits. C. sinensis essential oil is a volatile aroma liquid principally composed of nonsynthetic hydrocarbon limonene. Transmission electron microscopy studies on the structure unveiled the presence of hollow quasi-spherical carbon nano-onion-like structures incorporated within graphene layers. The as-fabricated nano-onion-incorporated graphene films exhibited a highly hydrophobic nature showing a water contact angle of up to 129 0 . The surface energies of these films were in the range of 41 to 35 mJ•m −2 . Moreover, a chemiresistive sensor directly fabricated using C. sinensis-derived onion-structured graphene showed a p-type semiconductor nature and a promising response to acetone at room temperature. With its unique morphology, surface properties, and electrical characteristics, this material is expected to be useful for a wide range of applications.

Hydrophilicity and Hydrophobicity Control of Plasma‐Treated Surfaces via Fractal Parameters

“…In our previous publications we attempted to relate some simple, physically clear integrative characteristics of complex nanomaterials to their practically applicable physical and chemical properties such as wetting, sensing, [4] antibacterial activity, [51] photocatalytic efficiency [52] and others. [3] The degree of spatial ordering in the nanostructured materials and the connectivity were considered as the characteristics that could possibly explain many important properties of a complex nanomaterial.…”

“…On the other hand, the samples for nano-scale (Figure 7b) shows improvement in the regularity with the treatment duration. In our previous works we have analyzed the influence of ordering to the surface characteristics [4,46] but here we try to relate the two important characteristics, namely fractality and ordering.…”

“…Complex nanomaterials and nanocomposites based on hierarchical surface structures are currently under extensive investigation. This is because such materials can be applied in a very broad range of contexts, [1][2][3] from sensors, [4][5][6] photocatalysts, [7] bio-electronic interface devices, [8] water repelling and self-cleaning materials, [9] various nanoelectronics devices [10,11] to even space technology applications such as photon-active diamond films for space propulsion [12,13] and nanostructured emitters for plasma propulsion systems [14,15] that are critical for miniaturized space assets. [16,17] It is not uncommon for the nanocomposites of this type to feature very complex surface, internal and interfacial structures that may in some instances form a fractal-like morphology.…”

Hierarchical Doped Gelatin-Derived Carbon Aerogels: Three Levels of Porosity for Advanced Supercapacitors

“…This suggests that the activation at 900 °C results in the most defective carbon, with 700 °C samples being the most graphitized and 800 °C samples possessing the properties that are somewhat in between the other sample types. The increase in the D band intensity was due to the doping of nitrogen, where all of the nitrogen atoms occupied the defective sites, causing the D band to increase [ 50 ]. The upshift from I D /I G ratio clearly shows that there is more disorder when the materials are activated at 900 °C, providing further evidence that there is more nitrogen being incorporated into the material [ 48 , 51 ].…”

Controlled Deposition of Nanostructured Hierarchical TiO2 Thin Films by Low Pressure Supersonic Plasma Jets

“…This is because of their wide range of available chemistries, different shapes of varying sizes, large surface-to-bulk ratios, and quantum-confinement effects at small length scales. Metallic and metal oxide nanoparticles and their thin films play particularly important roles in the advancement [ 1 , 2 ] of sensors [ 3 , 4 , 5 ], photocatalysts [ 6 , 7 ], bio-electronic-based devices [ 8 , 9 ], super-hydrophobic and self-cleaning materials [ 10 , 11 ], and various nanoelectronic devices [ 12 , 13 ]. In addition, light-sensitive diamond films have found applications in space technology [ 14 ], while other types of nanostructured aggregates are promising for the achievement of propulsion systems based on plasma technologies [ 15 , 16 ].…”