Synthesis Of Carbon-based Materials Research Articles

Carbon-based material derived from biomass waste for wastewater treatment

Biomass waste has known as a new precursor for the production of carbon-based materials due to its carbon richness, low cost, ease to access, ubiquitous, renewable and environmental-friendliness. In this publication, the study on the availability of biomass waste and the carbon-based materials (CBMs) for wastewater treatment application is reviewed and addressed. This paper discussed several types of CBMs such as activated carbon, graphene, carbon nanotubes, biochar, and carbon aerogel. The production of these different CBMs and their modification are given special attention. As harmful organic, dyes, and inorganic pollutants emerging from the wastewater has caused damage to the environment and water supplies, adsorption is the most widely utilised conventional technology for the removal of hazardous pollutants due to its ease of use and relatively cheap in comparison with other emerging methods. This corresponds to the CBMs which mainly works on the adsorption mechanism to perform the wastewater treatment. There are three kinds of biomass waste being explained which are sewage sludge, lignocellulosic, and cotton-based waste. This paper also extensively summarised a multitude of aspects regarding the biomass waste and the CBMs derivation from biomass waste. The challenges on the synthesis of CBMs from biomass was also included. In summary, the conclusion and future direction of the research were also discussed.

Pore-assisted lithium deposition in hierarchically porous and hollow carbon textile for highly stable lithium anode

Lithium (Li) metal is widely accepted as the most promising anode for next-generation batteries due to its highest theoretical capacity (3,860 mA h g−1) and lowest electrochemical potential (−3.04 V versus standard hydrogen electrode). However, Li-metal anodes suffer from low Coulombic efficiency and safety issues, due to the high activity and uncontrollable Li dendrite growth. Here, we demonstrate that a novel two-stage “outside-in” Li deposition behavior achieved through the use of bio-derived hollow carbon fiber textile with unique hierarchical porosity. We show that Li deposition first occurs on the external surface because of the abundant lithiophilic pores, followed by deposition both inside and on the wall of the hollow carbon fiber. This pore-induced mechanism is crucial for the carbon fiber textile serving as a stable and robust host for uniform Li deposition. This Li composite anode exhibits a high Coulombic efficiency for more than 500 cycles and high cycling stability of over 1,400 h at a current density of 1 mA cm−2. The scalable production and the novel understanding on the function of hierarchical porous structure provide critical insights into design and synthesis of carbon-based materials as hosts for Li anodes.

Stabilization of Titanium Dioxide Nanoparticles at the Surface of Carbon Nanomaterials Promoted by Microwave Heating.

TiO2 is frequently combined with carbon materials, such as reduced graphene oxide (RGO), to produce composites with improved properties, for example for photocatalytic applications. It is shown that heating conditions significantly affect the interface and photocatalytic properties of TiO2 @C, and that microwave irradiation can be advantageous for the synthesis of carbon-based materials. Composites of TiO2 with RGO or amorphous carbon were prepared from reaction of titanium isopropoxide with benzyl alcohol. During the synthesis of the TiO2 nanoparticles, the carbon is involved in reactions that lead to the covalent attachment of the oxide, the extent of which depends on the carbon characteristics, heating rate, and mechanism. TiO2 is more efficiently stabilized at the surface of RGO than amorphous carbon. Rapid heating of the reaction mixture results in a stronger coupling between the nanoparticles and carbon, more uniform coatings, and smaller particles with narrower size distributions. The more efficient attachment of the oxide leads to better photocatalytic performance.

Ionic Liquid Based Approaches to Carbon Materials Synthesis

AbstractIonic liquids (ILs) have attracted continuous interest because of their remarkable physicochemical properties, including high thermal and chemical stability, nonflammability, negligible vapor pressure, designable cation/anion pairs, electrical and ionic conductivity, low melting points, and affinity towards many compounds. These properties make ionic liquids valuable in the creation of new materials and new processes throughout almost the entire field of materials chemistry. An emerging field is the use of ionic liquids in carbon‐based nanomaterials. Initially, ionic liquids were used as self‐templating carbon sources for the generation of unusual carbon materials in which homogeneous heteroatom doping (e.g., N, B, S) can be accomplished fairly easily. Later, ionic liquids were recognized as suitable for use in the conversion of biomass into porous carbon materials, acting as both reaction media and porosity‐directing regulator. Such applications open the door towards the synthesis and accurate tuning of carbon nanostructures, for example, pore structure, morphology, heteroatom doping, and surface functionality. In addition, the hybridization of ionic liquids and nanocarbons enables the development of composites by combining the properties of the ionic liquid (e.g., ionic conductivity or catalytic activity) and those of a host (e.g., chemical or mechanical stability). Currently, although the research of this topic is rapidly expanding, the rational design and synthesis of carbon‐based materials, particularly their applications in energy storage and transformation, is still in its infancy. In this review, we focus on several aspects of ionic liquid derived carbons with the aim of shedding light on this new topic: 1) Ionic liquids as an advanced medium for carbon synthesis, 2) ionogels derived from nanocarbon, 3) ionic liquids as fluid precursors for functional carbons, and 4) ionic liquid derived carbons for heterogeneous catalysis.

A facile self-template strategy to fabricate three-dimensional nitrogen-doped hierarchical porous carbon/graphene for conductive agent-free supercapacitors with excellent electrochemical performance

Carbon materials with large surface area, high conductivity and suitable pore distribution are highly desirable for high-performance supercapacitors. The paper reported a self-template strategy for the fabrication of three-dimensional nitrogen-doped hierarchical porous carbon/graphene (3D-NHPC/G). The mixture of beer yeast cells, graphite oxide, urea, potassium hydroxide and phytic acid was dispersed in water by ultrasonication to form homogeneous slurry, which was then dried by spray drying and finally heated at 850°C in Ar/H2 environment. The study shows that such a new strategy creates a 3D carbon framework, hierarchical pore distribution, moderate graphitization and appropriate nitrogen doping. The as-prepared 3D-NHPC/G offers excellent dispersion, specific surface area of 3108.7 m2g−1 and electronic conductivity of 3096 S m−1, which is more than six-fold that of 3D-NHPC (494 S m−1). Owing to the greatly enchanced electron transfer and mass transport, the 3D-NHPC/G electrode displays the largely enhanced electrochemical performance. In 6mol l−1 potassium hydroxide aqueous electrolyte, its specific capacitance is 318 F g−1 at the current density of 1 A g−1, 277 F g−1 at the current density of 10 A g−1, and 155 F g−1 at the current density of 100 A g−1 that can remain at least 96.5% after 10000 cycles. In 1mol l−1 tetraethylammonium tetrafluoroborate organic electrolyte, the specific capacitance is 138 F g−1 at the current density of 1 A g−1 and 109 F g−1 at the current density of 10 A g−1. The study also provides an approach for design and synthesis of carbon-based materials with high supercapacitor behaviors.

Synthesis and Characterization of Silicon and Nitrogen Containing Carbon-Based Crystals and Their Nanostructured Materials

The synthesis of carbon-based materials, such as man-made diamonds, superhard C3N4 materials, SiCN crystals, and other carbon-based nanostructured materials, has attracted considerable attention for many decades in academic and industrial communities. However, so far, researchers have not successfully linked the growth mechanisms of carbon-based materials deposited under different synthetic conditions and methods. In fact, a single machine may produce many of these materials. This paper is aimed to study the linkages among various carbon-based materials synthesized on Si wafers using the same microwave plasma chemical vapor deposition system, including SiCN crystalline films, SiCN nanotubes, carbon nanotubes (CNTs), conical carbon nanorods, and other nanostructured materials.