Conversion of Alumina to Aluminum Nitride Using Polymeric Carbon Nitride as a Nitridation Reagent

Abstract

Polymeric carbon nitride, which was synthesized by polymerization of dicyandiamide at 500°C, was used as a nitridation reagent in the conversion of d-alumina (d-Al 2 O 3 ) to aluminum nitride (AlN). The products obtained at various reaction temperatures were characterized by powder X-ray diffraction, 27 Al magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). d-Al 2 O 3 began to convert to AlN at 900°C, which is the lowest temperature reported for the formation of AlN from Al 2 O 3 , and completely converted to AlN at 1400°C. The occurrence of reaction intermediates during nitridation was confirmed by 27 Al MAS NMR and XPS. The change in Raman spectra with reaction temperatures indicated that lattice defects in AlN were reduced by calcining at higher reaction temperatures.

Towards Macroporous α-Al2O3—Routes, Possibilities and Limitations

“…Niu et al introduced carbon nanotubes as templates into their alumina sol [50]. Consequently, they also followed a similar procedure as in described in the above-mentioned patents, i.e., the alleged transformation from γ-Al 2 O 3 into α-Al 2 O 3 was performed under N 2 flow at 1150-1300 • C, followed by pyrolytic carbon removal by oxidation at 500-750 • C. Products obtained via this method are certainly porous, and likely alumina, despite the possibility of aluminum nitride formation above 900 • C [51][52][53][54]. However, the authors of this review contest the formation of 100% pure corundum under the conditions described.…”

A General Synthesis of Porous Carbon Nitride Films with Tunable Surface Area and Photophysical Properties

“…[19] For Al/g-CN film, AlÀN bond is observable at the interface (Supporting Information, Figure S24). [20] The strength of this method is demonstrated by the facile patterning and scalability of the g-CN layer on different substrates. With the aid of a specific mask (Supporting Information, Figure S25), g-CN patterns can be deposited on various supports (Figure 4 c).…”

Carbothermal Reduction Synthesis of Aluminum Nitride from Al(OH)3/C/PVB Slurries Prepared by Three-Roll Mixing

“…In addition, the detailed mechanism of the carbothermal reduction reaction between different raw materials was not fully understood. It was still common to see the reports improving the types of raw materials [ 11 , 12 , 13 ], using the suitable additives [ 14 , 15 , 16 ] and preparing the near-spherical AlN powder [ 17 , 18 ] in recent years.…”