Borocarbonitrides

Borocarbonitrides are two-dimensional compounds that contain boron, nitrogen, and carbon atoms in a ratio BxCyNz.[1][2] Borocarbonitrides are distinct from B,N co-doped graphene in that the former contains separate boron nitride and graphene domains as well as rings with B-C, B-N, C-N, and C-C bonds.[3] These compounds generally have a high surface area, but borocarbonitrides synthesized from a high surface area carbon material, urea, and boric acid tend to have the highest surface areas.[1][4][5] This high surface area coupled with the presence of Stone-Wales defects in the structure of borocarbonitrides also allows for high absorption of CO2 and CH4, which may make borocarbonitride compounds a useful material in sequestering these gases.[1][4]

A schematic of borocarbonitride (BCN)

Electrical

The band gap of borocarbonitrides range from 1.0–3.9eV[1] and is dependent on the content of the carbon and boron nitride domains as they have different electrical properties.[1] Borocarbonitrides with a high carbon content have lower bandgaps[2] whereas those with higher content of boron nitride domains have higher band gaps.[1] Borocarbonitrides synthesized in gas or solid reactions also tend to have large bandgaps and are more insulating in character.[1] The wide range of composition of boronitrides allows for the tuning of the bandgap, which when coupled with its high surface area and Stone-Wales defects may make boronitrides a promising material in electrical devices.[2][6]

Synthesis

Solid state reaction

A high surface area carbon material such as activated charcoal, boric acid, and urea are mixed together and then heated at high temperatures to synthesize borocarbonitride.[2] The composition of the resulting compounds may be changed by varying the concentration of the reagents as well as the temperature.[1]

Gas phase synthesis

In chemical vapor deposition, boron, nitrogen, and carbon precursors react at high heat and are deposited onto a metal substrate.[1] Varying the concentration of precursors and the selection of certain precursors will give different ratios of boron, nitrogen, and carbon in the resulting borocarbonitride compound.[2]

Borocarbonitride composites

Borocarbonitride can also be synthesized by random stacking of boronitride and graphene domains through covalent interactions[2] or through liquid interactions.[1] In the first method, graphene and boron nitride sheets are functionalized and then are reacted to form layers of borocarbonitride.[2] In the second method, boron nitride and graphite powder are dissolved in isopropanol and dimethylformamide, respectively, and then sonicated.[2] This is then exfoliated to isolate borocarbonitride layers.

References
  1. kumar, Nitesh; Moses, Kota; Pramoda, K.; Shirodkar, Sharmila N.; Mishra, Abhishek Kumar; Waghmare, Umesh V.; Sundaresan, A.; Rao, C. N. R. (2013-04-23). "Borocarbonitrides, BxCyNz". Journal of Materials Chemistry A. 1 (19): 5806. doi:10.1039/c3ta01345f.
  2. Rao, C. N. R.; Gopalakrishnan, K. (2016-10-31). "Borocarbonitrides, BxCyNz: Synthesis, Characterization, and Properties with Potential Applications". ACS Applied Materials & Interfaces. 9 (23): 19478–19494. doi:10.1021/acsami.6b08401. PMID 27797466.
  3. Rao, C. N. R; Maitra, Urmimala (2015-01-01). "Inorganic Graphene Analogs". Annual Review of Materials Research. 45 (1): 29–62. Bibcode:2015AnRMS..45...29R. doi:10.1146/annurev-matsci-070214-021141.
  4. Raidongia, Kalyan; Nag, Angshuman; Hembram, K. P. S. S.; Waghmare, Umesh V.; Datta, Ranjan; Rao, C. N. R. (2010-01-04). "BCN: A Graphene Analogue with Remarkable Adsorptive Properties". Chemistry – A European Journal. 16 (1): 149–157. doi:10.1002/chem.200902478. PMID 19946909.
  5. Rao, C. N. R.; Ramakrishna Matte, H. S. S.; Maitra, Urmimala (2013-12-09). "Graphene Analogues of Inorganic Layered Materials". Angewandte Chemie International Edition. 52 (50): 13162–13185. doi:10.1002/anie.201301548. PMID 24127325.
  6. Gopalakrishnan, K.; Moses, Kota; Govindaraj, A.; Rao, C. N. R. (2013-12-01). "Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides". Solid State Communications. Special Issue: Graphene V: Recent Advances in Studies of Graphene and Graphene analogues. 175–176: 43–50. Bibcode:2013SSCom.175...43G. doi:10.1016/j.ssc.2013.02.005.
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