Investigation on ammonia-free scalable cobalt-doped hexagonal boron nitride for environmental remediation

Hexagonal boron nitride (h-BN) nanocrystals are of greater importance for wastewater remediation, and synthesizing these h-BN nanocrystals with high surface area adds significance. Hence a facile and economically viable hydrothermal technique was adopted to synthesize an ammonia-free nanocrystals using a nitrogen-rich organic compound. In this h-BN nanocrystals, cobalt (Co) was incorporated with varying weight% in order to further enhance the performance rate of the as-synthesized nanocrystals. Furthermore, the as-synthesized material was investigated to analyse various properties including structural, optical, elemental, functional and morphological. For analysing the structural property X-Ray diffraction technique was used which revealed the hexagonal phase of as-synthesized BN whereas for the functional property Fourier Transform Infrared spectroscopic study was performed which showed strong vibrations for B-N. In case of the optical property analysis, UV-Visible spectroscopic analysis was performed which depicted the decrease in bandgap from 5.12 to 2.93 eV and exhibited a redshift with respect to increase in dopant concentration. Elemental composition and oxidation states of the elements were investigated through X-ray Photoelectron Spectroscopy and the peak positioned at 193.9 eV exhibited the presence of B-N bond. In addition, pristine h-BN and Co-doped h-BN nanocrystals were assessed for degrading the Methylene blue (MB) dye and 10% Co-doped h-BN nanocrystals. Interestingly, 10 wt% doped h-BN nanomaterial exhibited superior catalytic activity and caused a 99.4% degradation of the MB dye in just 9 min. This percentage increase of degradation is probably due to an enhancement of existing adsorption and catalytic sites on photocatalysts.