Carbon Nano-onions Research Articles

Ni3+-Rich Ni/NiOx@C Nanocapsules Below 4nm Constructed by Low-Temperature Graphitization of Self-Assembled Few-Layer Coordination Polymers toward Efficient Alkaline Hydrogen Evolution Electrocatalysis.

Low-cost and eco-friendly Ni/NiO heterojunctions have been theoretically proven to be the ideal candidate for stepwise electrocatalysis of alkaline hydrogen evolution reaction, attributed to the preferred OHad adsorption by incompletely filled d orbitals of NiO phase and favorable Had adsorption energy of Ni phase. Nevertheless, most Ni/NiO compounds reported so far fail to exhibit excellent catalytic activity, possibly due to the lack of efficient electron transport, limited interfacial active sites, and unregulated Nin+ ratios. To address the above bottlenecks, herein, the ultrasmall Ni/NiOx@C nanocapsules (<5nm) are directly constructed by graphitization of four-layer Ni-based coordination polymers at record low temperatures of 400 °C. Ascribed to the accelerated electron and mass transfer by the carbon nano-onions coated around Ni/NiOx heterojunctions, the extreme rise in interfaces and Ni3+ defects with t6 2ge1 g electronic configuration owed to the ultrasmall size, the Ni/NiOx@C nanocapsules exhibit the highest catalytic activity and the lowest overpotential of η10 = 80mV among various Ni/NiO materials (measured on the glassy carbon electrode). This work not only constructs an industrialized high-efficiency electrocatalyst toward alkaline HER, but also provides a novel strategy for the constant-scale preparation of multicomponent transition metals-based nanocrystals below 4nm.

Investigating the Potential of Ghee Precursor-Derived Carbon Nano Onions for Enhancing Interfacial Bonding in Thermoplastic Composites.

In this study, we employed a straightforward flame synthesis process to produce carbon soot containing carbon nano onions (CNOs) using easily accessible ghee oil as a precursor. The ghee oil, with a molecular composition rich in more than 50 carbon atoms, served as an effective source for generating CNOs. The synthesized CNO particles underwent comprehensive characterization through high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses, providing a detailed account of their physicochemical properties. In addition, we explored the direct deposition of CNOs on carbon fiber (CF) surfaces for 5 and 10 min via a soot deposition process. The resulting freeze-fracture images obtained from scanning electron microscope (SEM) offered insights into the morphology of the CNO-deposited CF. Our study aims to shed light on the potential applications of CNOs, focusing on their characterization and the possible benefits they may offer in diverse fields, including but not limited to enhancing interfacial bonding in thermoplastic composites.

Ultra-fast microwave catalytic degradation of multiple dyes by waste derived carbon nano onions

The industrial revolution gave rise to unmitigated pollution of water bodies, posing a significant pitfall to social well-being through the presence of harmful dye pollutants. To address this challenge, the utilization of waste frying oil derived carbon nano onions (CNOs) for the simultaneous and ultra-fast degradation of multiple organic dyes and their mixtures in wastewater under microwave exposure is reported herein. The unique structure of CNOs plays a crucial role to facilitate effective degradation of complex organic dyes. The microwave catalytic degradation by CNOs achieved rapid removal of cationic crystal violet (∼98% in 5 min), rhodamine B (∼99% in 6 min) and methylene blue (∼99% in 6 min). While degradation of anionic congo red took 9 min to achieve ∼98% removal. Remarkably, when dealing with a mixture of anionic and cationic dyes, CNOs exhibited exceptional degradation efficiency (∼99%) of mixture of dyes in just 3 min. The data acquired from the time study was most accurately fitted in pseudo-first-order kinetics. Based on observations during trapping, it was determined that superoxide and hydroxyl radicals are the most responsible agents for the microwave catalytic dye degradation. The plausible mechanism for the microwave assisted dye degradation with CNOs is also investigated. Remarkably, CNOs exhibited fairly good recycling and reusing efficiency with worthy structural and chemical stability. The total organic carbon (TOC) content in the treated water has been reduced to 87.35% as compared to mixed dye solution after the five cycles of treatment. The rapid removal activity, recyclability, reusability and cost-effective nature of CNOs exhibit remarkable potential for high-throughput environmental remediation in real-world wastewater applications, which is of great importance in the field.

Exploitation of carbon surface functionality toward additive‐free formation of gold nanocuboids suitable for sensitive assay of N‐acetylcysteine in pharmaceutical formulations

AbstractChemical additive and physical template‐free electrochemical methods to prepare carbon‐supported nanostructures of catalyst metals represent an emerging technology. Formation of the metal nano/microstructures depends not only on the electrochemical method/parameters but also on the nature of the underlying carbon material. Here, we present a comparative evolution of unevenly distributed coral‐like aggregates of nanocuboid‐shaped gold nanostructures (AuNCBs) on the oxidised form of boron, nitrogen‐doped carbon nanoonions (oxi‐B,N‐CNO) compared to evenly distributed bud‐like aggregates of cubic shaped gold nanostructures on bare glassy carbon electrode under a similar electrochemical approach. The synthesis method provided the best availability of the surface active sites, whereas the shape of the structures showed a direct influence of both outer‐sphere and inner‐sphere electron transfer reactions. The higher sensitivity of AuNCBs@oxi‐B,N‐CNO compared to individual components and bare carbon/gold electrodes toward the inner‐sphere oxidative reaction of N‐acetyl‐L‐cysteine (NAC) was exploited in order to develop an electrochemical assay method with sensitivity and linear dynamic range of (4.70 ± 0.25) × 10−4 C∙cm−2∙mM−1 and 0.2–2.5 mM, respectively in acetate buffer (pH 4.45). Furthermore, the sensor design was deployed in the quantitation of NAC in pharmaceutical preparations, resulting in 89%–106% recovery.

Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy.

Nanocarbons are emerging at the forefront of nanoscience, with diverse carbon nanoforms emerging over the past two decades. Early cancer diagnosis and therapy, driven by advanced chemistry techniques, play a pivotal role in mitigating mortality rates associated with cancer. Nanocarbons, with an attractive combination of well-defined architectures, biocompatibility, and nanoscale dimension, offer an incredibly versatile platform for cancer imaging and therapy. This paper aims to review the underlying principles regarding the controllable synthesis, fluorescence origins, cellular toxicity, and surface functionalization routes of several classes of nanocarbons: carbon nanodots, nanodiamonds, carbon nanoonions, and carbon nanohorns. This review also highlights recent breakthroughs regarding the green synthesis of different nanocarbons from renewable sources. It also presents a comprehensive and unified overview of the latest cancer-related applications of nanocarbons and how they can be designed to interface with biological systems and work as cancer diagnostics and therapeutic tools. The commercial status for large-scale manufacturing of nanocarbons is also presented. Finally, it proposes future research opportunities aimed at engendering modifiable and high-performance nanocarbons for emerging applications across medical industries. This work is envisioned as a cornerstone to guide interdisciplinary teams in crafting fluorescent nanocarbons with tailored attributes that can revolutionize cancer diagnostics and therapy.

Folic acid-enhanced carbon nano onions illuminate the future of targeted cancer therapy: An experimental-cum-modeling study

Folic acid-enhanced carbon nano onions illuminate the future of targeted cancer therapy: An experimental-cum-modeling study

Low secondary electron emission characteristics of carbon nano-onion coating via plasma enhanced chemical vapor deposition

Suppression of secondary electron emission (SEE) by surface coating technology on metal materials has important applications in many fields, for which the investigation on new coating materials with low secondary electron yield (SEY) is desired significantly. In this study, the maximum SEY of nickel (Ni) substrate was reduced from 2.30 to 0.75 (67 % reduction) after a carbon nano-onion (CNO) coating prepared by plasma enhanced chemical vapor deposition (PECVD), and the SEY less than 1 means that some problems caused by secondary electron (SE) multiplication on metal materials could be solved completely. Various measurements, material characterization and CASINO Monte Carlo model simulation indicated that the low SEY characteristic of CNO coating could be attributed to two main mechanisms: Firstly, true SEs emitted from the surface of CNO could be reabsorbed by the adjacent CNO attributed to the micrometer scale undulating structure formed by the accumulation of CNO on the coating surface; Secondly, the defects degree of CNO directly affects the emission of true SE, which plays the role of low-energy electron capturing trap. This discovery can provide a reference for future coating production.

The Role of Fullerenes in Neurodegenerative Disorders

The use of carbon nanomaterials including fullerenes, carbon nanotubes, carbon nano-onions, carbon dots and carbon quantum dots for environmental applications has increased substantially. These nanoparticles are now used in the development of sensors and switches, in agriculture as smart fertilizers and in the biomedical realm for cancer therapy intervention, as antioxidants, in gene delivery and as theranostics. Here, we review the role of fullerenes as neuroprotectants. Their sp2 hybridized architectures and ability to intervene in the soluble-to-toxic transformation of amyloidogenic trajectories is highlighted here, along with other physico–chemical properties that impact interventional efficacy. Also highlighted are drawbacks that need to be overcome and future prospects.

Manipulating the Curie point in γ-Fe filled carbon nano-onions: The role of Mn and Gd for enhanced magnetic functionalities

Recent works have proposed the stabilization of γ-Fe nanocrystals inside carbon nano-onions (CNOs) and nanotubes (CNTs) as active ferromagnetic phases for possible applications in hyperthermic dissipative systems. Stabilization of the γ-phase of iron is of particular interest due to the unit-cell dependent ferromagnetic properties and controllable Curie point. Here we investigate a modification of the chemical vapor synthesis (CVS) method for the in-situ manipulation of γ-Fe nanocrystals within CNOs, in presence of bis(isopropyl-cyclopentadienyl)manganese or tris(tetramethyl-cyclopentadienyl)gadolinium(III) as additional growth-precursors. In the presented experiments ferrocene, dichlorobenzene and sulfur mixtures were employed with a fixed ratio. Interestingly, when employing bis(isopropyl-cyclopentadienyl)manganese we demonstrate the stabilization of a modified FCC γ-Fe phase inside the CNOs, identifiable as a γ-Fe23C6 through X-ray diffraction and refinement of the structural model (obtained by employing the Rietveld method), with unit cell parameters a=b=c= 10.5569 Å and space group Fm-3m. The relative amount of Mn content was found to vary from 0.2% to 0.5%. Differently, comparative experiments performed in presence of great excess of tris(tetramethylcyclo-pentadienyl)gadolinium(III) reveal a significant variation of the sample’s morphology, with the nucleation of Gd nanoparticles around γ-Fe filled CNOs. Magnetic characterization with field-dependent zero field cooled (ZFC) and field cooled (FC) acquisitions revealed for the first batch of experiments (method 1) a ferromagnetic behavior comparable to that of γ-Fe, with a T1 Curie point located in proximity of T∼ 400 K and a T2 Curie point in proximity of T∼90 K. Differently, for method-2, an important interplay of ferromagnetic and paramagnetic components was found in the Gd-decorated γ-Fe filled CNOs, with a reduction of the Curie point down to T∼350 K. The presented findings highlight the important role of 1) the γ-Fe23C6 phase in enhancing the saturation magnetization Ms of the filled CNOs and 2) the crystallinity of the Gd-component in allowing for an enhancement of the paramagnetic response in the filled CNOs.

A Simple Highly Efficient Catalyst with NiOX‐loaded Reed‐based SiC/CNOs for Hydrogen Production by Photocatalytic Water‐splitting

AbstractThe cocatalyst and the semiconductors are tightly coupled to achieve effective separation of charges, which is one of the effective ways to improve photocatalytic hydrogen production in recent years. In this report, natural reed as raw material was simple sintering to obtain silicon carbide (SiC) nanowires supported on carbon nano onions (CNOs), and NiOX as a cocatalyst was introduced and evenly distributed on the SiC and CNOs to form a NiOX/SiC/CNOs heterojunction composite, which can be used for photocatalytic hydrogen production under visible light. The structure and performance of the composite were investigated by XRD, XPS, TEM, SEM, FTIR, GC, etc. The results show that the NiOX/SiC/CNOs composite performed excellent photocatalytic activity, When the loaded NiOX is 1.0 wt %, the maximum hydrogenation rate can reach 3160.2 μmol ⋅ g−1 h−1 in the presence of Eosin Y (EY) as photosensitizer and triethanolamine (TEOA) as a sacrificial agent, which is 2.86 times that of SiC/CNOs. The improvement in photocatalytic performance was mainly attributed to synergistic effects of high light absorbing efficiency, effective charge separation, increasing the transfer rate of electrons, and NiOX high dispersion active sites in SiC/CNOs.

Synthesis and Electrochemical Applications of Carbon Nano-onions

Abstract: Carbon nano-onions, a family of carbon nanomaterials, consist of multiple concentric fullerene- like carbon shells which are highly defective and disordered. Due to their unique physicochemical properties, such as high conductivity, high surface area, biocompatibility, thermal stability, and others, they are promising nanomaterials for different electrochemical applications. In this sense, this review outlines the synthetic methods available to afford carbon nano-onions in their pristine, functionalized (covalent and non covalent) and doped forms and their use in energy storage, electrocatalysis and sensing. Particularly, we review the performance and properties of carbon nano-onions as electrode materials for supercapacitors, electrocatalysts in different reactions for fuel cells, and electrode materials for sensors. In the last decade, as we will discuss, scientists have found that functionalized and doped carbon nano-onions have better electrochemical properties than pristine carbon nanoonions, such as specific capacitance, surface wettability, energy power, adsorption on an electrode surface, and charge delocalization, among others.

Preparation of a new composite based on multilayer fullerene with mesoporous carbon nitride and its application in the extraction of tacrolimus and everolimus from plasma prior to LC-MS/MS analysis.

The development of new and efficient adsorbents for dispersive solid-phase extraction method, particularly prior to chromatography analysis, is increasing. In particular, this method is recommended for use before biological sample analysis. In this work, a new composite was prepared from mesoporous carbon nitrides and carbon nano-onions and was utilized for the extraction of tacrolimus and everolimus from plasma samples prior to high-performance liquid chromatography-tandem mass spectrometry analysis. To achieve this aim, first, mesoporous carbon nitrides and carbon nano-onions were synthesized separately and mixed at optimized proportions. Subsequently, a suitable amount of the prepared composite (5 mg) was added to 2 mL of sample solution containing the analytes under vortexing. Next, the extracted analytes were eluted using acetonitrile. The approach was linear within the ranges of 1.0-500 and 0.51-500 ng mL-1 for tacrolimus and everolimus, respectively. Sensitive limits of detection (0.31 and 0.15 ng mL-1 for tacrolimus and everolimus, respectively), acceptable relative standard deviations (intra- and inter-day precisions of ≤5.6% and high extraction recoveries of 71.0% and 83.0% for tacrolimus and everolimus, respectively) were obtained. The results showed that the method can be successfully applied in the simultaneous extraction of the studied analytes from plasma.

Memristive effects within stacking faults consisting of locally coexisting rhombohedral and Bernal lattices in exfoliated graphite and multilayered carbon nano-onion

We report an in-depth investigation of stacking faults in exfoliated pyrolytic graphite and in multilayered lattices of carbon nano-onions by employing a combination of atomic force microscopy (AFM) and Raman point and mapping spectroscopy.

Ecologically viable carbon nano-onions for the efficient removal of methyl orange azo dye and its environmental assessment

The performance of carbon nano-onions in removing methyl orange dye from wastewater.

Electrical nature of randomly oriented low-dimensional structural hybrids of carbon.

Low-dimensional carbon materials are of great interest and have tremendous potential for application in flexible plastic electronics. However, the development of devices based on carbon structural hybrids is often hindered due to the high recombination rate of photoexcited charges, low absorbance, and other factors. This work discusses the emergence of multi-component structural forms of carbon from single-wall carbon nanotubes (SWCNTs) and demonstrates the electrical nature of the film containing these heterogeneous low-dimensional structural derivatives that are amalgamated in a polyurethane matrix. SWCNTs serve as a building block to give rise to multi-structural compounds, including multi-wall carbon nanotubes (MWCNTs), graphene sheets (GSs), carbon nanoscrolls (CNS), 'Y' and 'T' junctions, twisted CNTs and carbon nano-onion (CNO)-like structures, after performing oxidative purification and covalent functionalization processes. These one- and two-dimensional (1D and 2D) components with different individual electrical characteristics when integrated in a polyurethane binder and spin-coated on a SiO2/Si substrate exhibit an overall semiconducting behaviour. Current (I)-voltage (V) characteristics reveal thermally driven photo-excited charges that are mainly responsible for the observed current trend of the film. Herein, we explore a facile cost-effective strategy to fabricate stable thin film coatings comprising a random network of functionalized structural derivatives of carbon and polymer conjugates and investigate the overall electrical nature to envisage incorporating these nanomaterials in future plastic electronics.

Stacking-faults and moiré superlattice nucleation within the graphitic layers of partially-collapsed carbon nano-onions filled with γ-Fe: the role of indium isopropoxide as a growth-promoter

We report the stabilization of hexagonal moiré-like superlattices in partially-collapsed carbon nano-onions (CNOs) by employing indium-isopropoxide as growth-promoter, during the pyrolysis of ferrocene, dichlorobenzene and sulfur mixtures.

One-Pot Sonochemical Synthesis of Carbon Nano-Onions from Silicon Carbide in Pure Water

One-Pot Sonochemical Synthesis of Carbon Nano-Onions from Silicon Carbide in Pure Water

Low carbon to metal ratio and nucleation of hexagonal moiré superlattices in onion-like graphitic-domains within the walls of carbon nanotubes by pyrolysis of ferrocene in viscous boundary layers

Developing advanced methods for the stabilization of low dimensional moiré superlattices and van Hove singularities in collapsed chiral single-wall carbon nanotubes (SWCNTS) or in partially collapsed carbon nano-onions (CNOs) is...

Enhancing pancreatic ductal adenocarcinoma (PDAC) therapy with targeted carbon nano-onion (CNO)-mediated delivery of gemcitabine (GEM)-derived prodrugs

Nanotechnology's potential in revolutionising cancer treatments is evident in targeted drug delivery systems (DDSs) engineered to optimise therapeutic efficacy and minimise toxicity. This study examines a novel nanocarrier constructed with carbon nano-onions (CNOs), engineered and evaluated for its ability to selectively target cancer cells overexpressing the hyaluronic acid receptor; CD44. Our results highlighted that the CNO-based nanocarrier coupled with hyaluronic acid as the targeting agent demonstrated effective uptake by CD44+ PANC-1 and MIA PaCa-2 cells, while avoiding CD44- Capan-1 cells. The CNO-based nanocarrier also exhibited excellent biocompatibility in all tested pancreatic ductal adenocarcinoma (PDAC) cells, as well as healthy cells. Notably, the CNO-based nanocarrier was successfully loaded with chemotherapeutic 4-(N)-acyl- sidechain-containing prodrugs derived from gemcitabine (GEM). These prodrugs alone exhibited remarkable efficacy in killing PDAC cells which are known to be GEM resistant, and their efficacy was amplified when combined with the CNO-based nanocarrier, particularly in targeting GEM-resistant CD44+ PDAC cells. These findings demonstrate the potential of CNOs as promising scaffolds in advancing targeted DDSs, signifying the translational potential of carbon nanoparticles for cancer therapy.

Waste frying oil derived carbon nano-onions as a cost-effective cathode material for high-voltage zinc-ion hybrid supercapacitors

Energy crisis and environmental pollution are two major worldwide issues that can be solved by developing sustainable, commercial, and long-durability energy storage systems from the reutilization of waste material. Waste frying oil, a known waste, is used as a carbon source for the synthesis of carbon nano-onions (CNOs) using economically viable and environmentally friendly wick pyrolysis techniques. The as-synthesized CNOs were used as a cost-effective cathode in zinc-ions hybrid supercapacitors (Zn–HSCs). CNOs with a fractal-like structure in an interconnected network and more accessible active available surface area provide great advantage as a cathode to fabricate Zn–HSCs. The CNOs-based active cathode material in aqueous Zn–HSCs presents a high specific capacitance of 342 F g−1 at a current density of 0.5 A g−1 under a high working potential window (0–1.9 V). Zn–HSCs achieve a maximum 8.2 kW kg−1 of power density and 164.33 W h kg−1 of energy density. More significantly, excellent long-term durability with 83 % of capacity retention and 100 % retention of coulombic efficiency was also achieved after 10,000 cycles at a high 10 A g−1 of current density. The overall work represents a way of utilizing waste frying oil as a cost-effective and efficient cathode material for aqueous Zn–HSCs, which could aid-in the commercialization of Zn–HSCs.