Natural precursor based hydrothermal synthesis of sodium carbide for reactor applications

Physica Status Solidi (b)

Sankararaman

2023

Self Cite

The advancement in semiconductor technology led to the development of novel materials with tailored properties. Besides the widely employed semiconductors like germanium, silicon, gallium arsenide, gallium nitride, gallium phosphide, cadmium sulfide, and composites, recently, the potential of carbide semiconductors has been widely explored to cater for the needs of the electronic industry. [1,2] Semiconducting thin films are extensively used in modern technological applications like plasma screen displays, organic light-emitting diodes, solar cells, and sensors. [2,3] Among the compound semiconductors, carbide-based electronic materials, primarily silicon carbide, are emerging as promising materials for applications demanding high power, fast switching speed, high temperature, better radiation tolerance, and high efficiency. [4,5] The success story of silicon carbide in electronics also tempted researchers to investigate other carbides.Carbides consisting of nonmetallic carbon (C) and metallic/semimetallic elements with lower electronegativity have various industrial uses due to their valuable structural and physical characteristics. [6,7] Although carbides have been used as refractory materials for more than a century, the scientific community is currently very interested in this material due to its use in a variety of scientific and technological disciplines. Carbides have uses in electronics and photonics in addition to the more conventional ones based on their durability and refractoriness. [5,6,[8][9][10] Excellent melting point and high chemical stability are crucial characteristics that define carbides as a refractory material. Covalent and interstitial carbides are found to satisfy these requirements. [6,7,11] Even if intermediate and salt-like carbides do not meet one or both of these requirements, they have industrial uses.Alkali, alkali earth, and group III metals with carbon combine to generate ionic carbides, sometimes referred to as salt-like (saline) carbides having extremely high ionic and electronegativity characteristics. The carbides formed by sodium are-Na 2 C 2 , NaC, NaC 64 , and NaC 2 with carbon atoms in chains, networks, and solitary. [9,12] These carbides have a graphite-like structure with metal atoms sandwiched in between the various layers of carbon atoms. The common type of saline carbide is the sodium carbide (Na 2 C 2 ), also known as disodium acetylide, which is an inert, clear material with no color. However, it quickly decomposes in the presence of acids/water/carbon, forming aliphatic hydrocarbons, which appear black or gray. Each Na þ ion in sodium carbide is surrounded by six C À ions that are in close proximity to it and vice versa. The ideal anti-CaF 2 structure is distorted by the spiral arrangement of the C 2 2À array in the sodium carbide structure. As a result, Na 2 C 2 crystallizes in an anti-CaF 2 structure deformed with a CC distance of 120 pm. The C 2 2À ions in them are loosely packed, which results in a low crystal density of 1.6 g cm À3 . [12,13] Sodium carbide f...

Section: Resultsmentioning

confidence: 99%

Divulging the Potential of Sodium Carbide Thin Film for Semiconductor Applications

Physica Status Solidi (b)

Sankararaman

2023

Self Cite

“…Among various carbides, BC has emerged as a potential candidate for diversified industrial applications because of its unique structural, chemical, and physical properties . It finds applications in military, nuclear, and ceramic industries apart from its optoelectronic applications .…”

Section: Introductionmentioning

confidence: 99%

Cost‐Effective Green Synthesis of Boron‐Rich Carbide Coatings for Infrared Windows and Night‐Vision Optics

Devi

Physica Status Solidi (a)

Sankararaman

2020

The increasing demand for infrared (IR) window materials for various applications in optical imaging systems necessitates the development of cost‐effective green techniques. Herein, the synthesis of refractory boron carbide (BC) using castor oil, as carbon precursor, and the preparation of IR transparent films by thermal vapor deposition technique is reported. Films are prepared with 1:3, 1:4, and 1:5 ratios of boric acid and castor oil, respectively. The X‐ray diffraction (XRD) and Fourier‐transform IR (FTIR) analyses reveal the structure of films prepared to be BC. The morphology of the films is analyzed by the atomic force microscopy (AFM) technique, and its dependence on precursor's ratio is also studied. The spectroscopic characterization by the ultraviolet–visible–near IR (UV–vis–NIR) transmittance study reveals the potential of the films for IR window applications. The bandgap energy of the BC films determined from the Tauc plot yields a value of 2.33 eV. The absorption coefficient, extinction coefficient, refractive index, dissipation factor, and optical conductivity are also studied from the reflectance and transmittance data.

“…It is well reported that natural fibers with cellulose as basic units can function as an excellent reinforcement material. [11] The thermal decomposition of carbon chain in cellulose enables the addition of semi-metal atoms like boron and the formation of respective carbides. The fact that plants contain cellulose suitable for turning into carbon precursors makes them the focus of research in green synthesis.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature green synthesis of boron carbide using aloe vera

SarithaDevi

Ambadas³

et al. 2018

Chinese Phys. B

Self Cite

The unique structural and physical properties of boron carbide, which make it suitable for a wide range of applications, demands the development of low-cost and green synthesis method. In the present work, the commonly available leaves of aloe vera are hydrothermally treated to form the carbon precursor for the synthesis of boron carbide. The morphological characterization reveals the porous nature of the precursor turning into a tubular structure upon boron carbide formation. The structural characterization by x-ray diffraction and other spectroscopic techniques such as Fourier transform infrared, Raman, photoluminescence and uv-visible near-infrared spectroscopy confirm the formation of boron carbide. The thermogravimetric analysis of the sample is found to exhibit good thermal stability above 500 • C. When the sample is annealed to 600 • C, boron carbide with phase purity is obtained, which is confirmed through XRD and FTIR analyses. The optical emission properties of the sample are studied through CIE plot and power spectrum. Compared with other natural precursors for boron carbide, the aloe vera is found to give a good yield above 50%.