Synthesis Of Hollow Carbon Nanospheres Research Articles

The synthesis of hollow carbon nanospheres from potato starch and the application in supercapacitor

The synthesis of high-valued carbon nanomaterials from biomass has always been a hot topic. The work reports the preparation of hollow carbon nanospheres (HCNs) from potato starch with one-step carbonization, in which self-made MgO powder is utilized as the template. In this study, an attempt was made to change carbonization temperature to control HCNs in diameter, wall thickness and pore distribution. Results show that the sample obtained at 800 °C (HCN-800) has a thinner wall thickness (about 12.1nm), smaller and more uniform diameter (average diameter of 46.2 nm), as well as possesses a high specific surface area (619.53 m2 g-1) and the largest pore volume (2.8994 cm3 g-1). An application in supercapacitor has been verified for the HCNs in the work. In the three-electrode system, the HCN-800 exhibits excellent electrochemical performance, such as superior specific capacitance (324.8 F g-1 at 0.5 A g-1), high rate performance (215.7 F g-1 at 50 A g-1) and outstanding cycling stability (92.83 % capacitance retention after 10,000 cycles). Moreover, an assembled symmetric supercapacitor shows an energy density of 11.1 Wh kg-1 at a power density of 427 W kg-1, far exceeding that of previously reported carbon electrode materials. In short, the work provides a novel way to synthesize high-value-added HCNs from cheap biomass precursors, which have potential applications in the field of supercapacitors and other energy storage devices.

Using waste to treat waste: facile synthesis of hollow carbon nanospheres from lignin for water decontamination.

Lignin, the most abundant natural material, is considered as a low-value commercial biomass waste from paper mills and wineries. In an effort to turn biomass waste into a highly valuable material, herein, a new-type of hollow carbon nanospheres (HCNs) is designed and synthesized by pyrolysis of biomass dealkali lignin, as an efficient nanocatalyst for the elimination of antibiotics in complex water matrices. Detailed characterization shows that HCNs possess a hollow nanosphere structure, with abundant graphitic C/N and surface N and O-containing functional groups favorable for peroxydisulfate (PDS) activation. Among them, HCN-500 provides the maximum degradation rate (95.0%) and mineralization efficiency (74.4%) surpassing those of most metal-based advanced oxidation processes (AOPs) in the elimination of oxytetracycline (OTC). Density functional theory (DFT) calculations and high-resolution mass spectroscopy (HR-MS) were employed to reveal the possible degradation pathway of OTC elimination. In addition, the HCN-500/PDS system is also successfully applied to real antibiotics removal in complex water matrices (e.g. river water and tap water), with excellent catalytic performances.

Application of Novel Hollow Carbon Nanosphere Drug-Loading System in Chemotherapy of Esophageal Squamous Cell Carcinoma.

With the continuous improvement of carbon nanotube synthesis and purification technology and the continuous improvement of carbon nanotube dispersion technology, carbon nanotubes have played an increasingly important role in the treatment of malignant tumours. One of the hot spots. Compared with other carbon nanotube materials, the carbon nanosphere drug loading system is more suitable for loading hydrophobic drugs, and the drug loading capacity is higher than other one-dimensional two-dimensional carbon nano-materials. In addition, carbon nanospheres of a suitable size are more easily absorbed by tumour cells and can carry a large amount of drugs for transport in the blood. And the pore structure of the carbon nanosphere is adjustable, and the drug release can be controlled by adjusting the pore size, and the pore diameter is generally less than 10 nm to prevent the drug from being released in advance. Esophageal cancer is one of the most frequently occurring malignancies in China, and the incidence of esophageal cancer ranks 8th in the world. Palliative chemotherapy is t he main treatment method for patients with advanced esophageal cancer. Simultaneous chemoradiotherapy has relatively obvious advantages in improving the survival rate of patients. It is of great significance to study the application of carbon nanosphere drug-loading system in chemoradiotherapy for esophageal squamous cell carcinoma. Therefore, in this study under the hydrothermal method, which is one of the commonly used methods for the synthesis of hollow carbon nanospheres, carboxymethyl chitosan was used as a carbon precursor, and the targeted drug erlotinib was loaded with carbon nanospheres. A new hollow nano-carbon sphere drug-loading system (HNCSDLS) was prepared and related characterizations were carried out. At the same time, the morphology, properties, in vitro and in vivo toxicity, bio-distribution, and anti-tumour activity of HNCSDLS were also studied in this study using scanning electron microscopy flow cytometry, laser confocal, spectrometer, cell proliferation experiment, and in vivo fluorescence imaging experiment Detection. The results of this study indicate that HNCSDLS has high biocom-patibility and stability, can be quickly distributed in the cytoplasm, and avoids lysosomal clearance. It can effectively deliver erlotinib to the tumour site, extend the drug's in vivo circulation time, inhibit tumour growth, reduce the toxicity of erlotinib to heart and kidney tissues, and increase its antitumor activity.

Facile Deflagration Synthesis of Hollow Carbon Nanospheres with Efficient Performance for Solar Water Evaporation.

Solar water evaporation is a promising and environment-friendly approach to relieve global water scarcity issues. Currently, many reports show that the voids and porous structure are beneficial to the absorption of solar energy to generate water steam. Herein, carbon nanospheres with central cavity structures are rationally designed by the one-step NaN3/fluorinated graphite deflagration method. The Na clusters derived from NaN3 deflagration are not only provided as the hollow templates but also react with fluorinated graphite to release heat, further boosting the formation of hollow carbon nanospheres (HCSs). Benefiting from the diversity of carbon nanomaterials, rough surface, unique hollow structures, and numerous micron/submicron holes, the light absorption ability, heat localization, and water supply capacity of HCSs have been significantly enhanced. Because of these advantages, the HCS-3 exhibits an excellent water evaporation efficiency of 92.7% at 1 kW m-2, which is much higher than that of carbon nanospheres, graphene oxide, and even most of the previous carbon materials. In addition, we demonstrated that the HCSs have a long-term stability and high efficiency of production of drinkable water and purifying various types of wastewater, including seawater, strong acid/alkaline water, and water containing dyes. To sum up, the deflagration synthetic technology as a facile and ultrafast process can be a new insight for future photothermal material design.

Facile Synthesis of Hollow Carbon Nanospheres by Using Microwave Radiation

Carbon-based nanomaterials have attracted much research interest in recent years due to their excellent chemical and physiological properties such as chemical stability, low cytotoxicity, and biocompatibility. The traditional methods to prepare hollow carbon nanospheres require complicated instrumentation and harsh chemicals, including high-temperature furnace, gas inlets, and hydrogen fluoride etching. Herein, we propose a new strategy to prepare hollow carbon nanospheres in a simple and fast manner by using microwave radiation. Polypyrrole-coated silica core-shell nanoparticles (SiO2@PPy NPs) were firstly prepared and subsequently processed by microwave radiation and aqueous alkaline solution to obtain the hollow carbon nanospheres. This facile method has potent potential to be utilized in the preparation of different types of hollow carbon nanospheres with various microstructure and elemental composition.

Facile Synthesis of Hollow Carbon Nanospheres and Their Potential as Stable Anode Materials in Potassium-Ion Batteries.

Hollow carbon nanospheres (HCNs) have found broad applications in a large variety of application fields. Unfortunately, HCNs are known for their tedious operations and are incompetent for scalable synthesis for those widely adopted nanocasting-based routes. Here, we report a facile and highly efficient method for the creation of hollow carbon structures by tuning the growth kinetics of its polymeric precursor. We identified that a controlled polymerization of Cu2+-poly(m-phenylenediamine) (Cu-PmPD) could form nanospheres with modulated inner chemical inhomogeneity, where the core of the particles was low in polymerization degree and water soluble, whereas the outer part was water insoluble. Therefore, a simple water washing of the prepared polymeric particles directly formed hollow nanospheres with a good control on the structural features including their cavity size and shell thickness. HCNs were formed through a following heat treatment and were able to exhibit promising potential as a stable anode material when tested in potassium-ion batteries.

Synthesis of hollow carbon spheres from polydopamine for electric double layered capacitors application

This paper reports a surfactant-assisted template method for synthesis of hollow carbon nanospheres by using polydopamine (PDA) as carbon source and ZnO as template. In the help of surfactant micelles, spherical ZnO particles are firstly formed and then coated with PDA films at room temperature without structure damage by the alkaline conditions needed for self-polymerization of dopamine. After carbonization in N2 atmosphere followed by ZnO removal, hollow carbon spheres with adjustable particle size (150–300 nm), high specific surface area (SSA, ~1100 m2 g−1) and optimized mesopore size distribution are obtained. The effects of surfactant content and carbonization temperature on the morphology and the electrochemical properties of the as-prepared carbons have been further investigated. The hollow carbon spheres obtained at optimum synthetic conditions exhibit outstanding electrochemical properties including high capacitance (156 F g−1 at 2 mV s−1) and rate capability (125 F g−1 even at 200 mV s−1) as well as cycling stability with 98% capacitive retention after 16,000 cycles, suggesting that it is a promising electrode material for the application of electric double layered capacitors.

Hollow Carbon Nanospheres with Tunable Hierarchical Pores for Drug, Gene, and Photothermal Synergistic Treatment.

Design and synthesis of porous and hollow carbon spheres have attracted considerable interest in the past decade due to their superior physicochemical properties and widespread applications. However, it is still a big challenge to achieve controllable synthesis of hollow carbon nanospheres with center-radial large mesopores in the shells and inner surface roughness. Herein, porous hollow carbon nanospheres (PHCNs) are successfully synthesized with tunable center-radial mesopore channels in the shells and crater-like inner surfaces by employing dendrimer-like mesoporous silica nanospheres (DMSNs) as hard templates. Compared with conventional mesoporous nanospheres, DMSN templates not only result in the formation of center-radial large mesopores in the shells, but also produce a crater-like inner surface. PHCNs can be tuned from open center-radial mesoporous shells to relatively closed microporous shells. After functionalization with polyethyleneimine (PEI) and poly(ethylene glycol) (PEG), PHCNs not only have negligible cytotoxicity, excellent photothermal property, and high coloading capacity of 482 µg of doxorubicin and 44 µg of siRNA per mg, but can also efficiently deliver these substances into cells, thus displaying enhanced cancer cell killing capacity by triple-combination therapy.

Combustion-mediated synthesis of hollow carbon nanospheres for high-performance cathode material in lithium-sulfur battery

Hollow carbon nanospheres as potential cathode materials for lithium-sulfur (Li-S) batteries were successfully synthesized using a metathesis reaction between sodium azide and halogen polymer. The reaction was driven by thermal heat from the exothermic recombination of Na+ and Cl− (or F−) ions into NaCl (or NaF) salts. The result was an increase of the overall system temperature up to 1320–1750 °C followed by the simultaneous formation of sodium halide-carbon core–shell nanoparticles. Therefore, hollow carbon nanospheres with diameter and shell thickness of ∼50–500 nm and ∼10–50 nm, respectively, were produced after water washing of the reaction product. The composite cathode materials for Li-S batteries were manufactured by infiltrating sulfur into the hollow core of nanospheres. The electrochemical cycling showed discharge capacity of ∼700 mAh g−1 (after 100 cycles) at 0.5 C current rate which is more than ∼2.4 times larger than that for the sulfur/carbon black composites prepared by the same technique. The enhancement of battery performance was attributed to the well-organized and unique 3D structure of hollow carbon, enabling better utilization of sulfur.

Template-less synthesis of hollow carbon nanospheres for white light-emitting diodes

A novel approach is demonstrated on the synthesis of hollow carbon nanospheres (HCNs) and their applications as color converter for white light-emitting diodes. HCNs were synthesized in a hydrothermal process using hexamethylenetetramine as precursor. The synthesis involves a template-less and one-step aqueous method for the first time, which enables the growth of HCNs with the temperature as low as 160°C. HCNs solutions exhibit strong yellow-green emission under ultraviolet light excitation and possess typical excitation-dependent photoluminescence (PL) behavior as carbon nanoparticles. We also used a facile coating method to coat a blue LED with HCNs layer which plays a role as color-converted phosphor. The LED shows bright white light, and the spectrum involves two main components, one from the blue LED chip centered at 455nm and one from HCNs centered at 520nm.

A simple SDS-assisted self-assembly method for the synthesis of hollow carbon nanospheres to encapsulate sulfur for advanced lithium–sulfur batteries

The hollow carbon nanospheres (HCNSs) were prepared using a simple SDS-assisted self-assembly method, and a sulfur–carbon composite based on HCNSs was synthesized for lithium–sulfur batteries by a vapor phase infusion method. The sulfur–HCNS composite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetry (TG) measurements. It is found that the elemental sulfur was dispersed inside the pores of carbon spheres. It is demonstrated from the galvanostatic discharge–charge process and cyclic voltammetry (CV) that the sulfur–HCNS composite has a large reversible capacity and an excellent cycling performance as cathode materials. The sulfur–HCNS composite with a sulfur content of 47.6 wt% displays an initial discharge capacity of 1031 mA h g−1 and a reversible discharge capacity of 477 mA h g−1 after 100 cycles at 0.5 C charge–discharge rate.

A novel route for preparation of hollow carbon nanospheres without introducing template.

A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only. Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM, and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2on the surface of carbon hollow spheres was processed, and its PL property was also characterized.

Synthesis of hollow carbon nanospheres through a ZnSe nanoparticle template route

In this paper, we report on the synthesis of hollow carbon nanospheres through a ZnSe nanoparticle template route. During the experimental process, carbon encapsulated ZnSe nanoparticles were synthesized by non-catalytic one-step thermal evaporation method. The structural characterizations reveal that formation of the carbon hollow spheres involves a thermal conversion process. This synthetic strategy might exploit a favorable route to synthesize carbon encapsulated semiconductor nanostructures and hollow nanostructures, which are potentially important for novel nano-science and technology.

Facile Synthesis of Hollow Carbon Nanospheres from Hollow Chitosan Nanospheres

Hollow carbon nanospheres (HCNS) with large surface area were synthesized from hollow chitosan nanospheres by one-step pyrolysis with a relatively low temperature (550 degrees C). The resulted HCNS is fully carbonized and partially graphitized under the experiment conditions. It is an important and facile method to prepare the uniform, shape- and size-controlled carbon nanomaterials by carbonization of the natural polysaccharide compounds and their derivatives. The as-prepared HCNS has a narrow size distribution in hollow carbon nanospheres (about 53 nm). The structure and size of HCNS are reproducible and could be tunable by changing the preparation conditions. The characterizations to estimate the composition, decompose properties, crystalline form, structure and surface property of the HCNS were investigated using FT-IR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction measurement (XRD), transmission electron microscopy (TEM) analysis, and the N2 adsorption-desorption isothermal process. The present preparation method makes it feasible to synthesize carbon nanospheres in abundance in the lab, and the synthesized HCNS could be a promising support for metal catalysts, an ideal matrix connecting with DNA or other bioactive substances.