Synthesis and characterization of BCN by using activated charcoal with the O’Connor method

Abstract

This study primarily focuses on boron carbon nitride (BCN) synthesis using the O’Connor method, a proven technique for solid-state boron nitride production. The process involved heating a mixture of boron oxide, urea, and activated charcoal in an ammonia gas atmosphere. Varied ratios of activated charcoal, ranging from 10 to 30% (w/w), were introduced into the boron oxide and urea mixture (1:2 w/w). The experiments aimed to investigate the influence of activated charcoal on BCN production, which was conducted in a controlled atmosphere tube furnace at 1450 °C for 3 h. Characterization of the resulting products employed Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy (EDS). FTIR analysis highlighted shoulder peaks at 1123 and 2349 cm⁻¹, indicative of single-bonded BC and triple-bonded CN. XRD patterns exhibited broadening with increased activated charcoal, suggesting the BCN nature of the structure. Furthermore, Rietveld refinement further supported the BCN system and molecular composition analysis via EDS measurements revealed the BCN triple system. Analysis of the data indicated a positive correlation between the molar ratio of charcoal and BCN production. Higher amounts of charcoal facilitated BCN formation, promoting carbon insertion into the BN layered structure.