BC₆N Monolayer as a Potential VOC Adsorbent in Mitigation of Environmental Pollution: A Theoretical Perspective

Rapid economic growth has led to severe air pollution, which poses threats to both the environment and public health. Among the major contributors to this issue are volatile organic compounds (VOCs), the abatement methods of which have received considerable attention from the research community. Recently, an adsorption technology employing two-dimensional monolayers has emerged as a promising strategy for VOC control. In the current investigation, we examined the adsorption behaviors of three prevalent VOCs, namely, acetone, benzene, and tetrachloromethane, on both pristine and Pd-doped BC₆N monolayers. Through first-principles calculations based on density functional theory, it was revealed that pristine BC₆N adsorbs acetone, benzene, and tetrachloromethane with modest adsorption energies of -0.003, -0.036, and -0.017 eV, respectively. These weak interactions make the adsorbate-adsorbent systems especially unstable, causing the VOCs to desorb from the pristine monolayer under increased ambient temperature or other environmental disturbances. The introduction of an interstitial Pd dopant has induced a significant improvement in the adsorption performance of the BC₆N monolayer. Specifically, the values of adsorption energy for acetone and benzene on the Pd-doped BC₆N monolayer experience a remarkable increase, measuring -0.745 and -1.028 eV, respectively. Moreover, the charge transfer is enhanced along with reduced adsorption distances, indicating strong chemisorption of acetone and benzene on the Pd-doped BC₆N monolayer. Our results establish the Pd-doped BC₆N monolayer as an efficient adsorbent for the toxic gases, particularly acetone and benzene, carrying practical implications for air quality improvement and environmental sustainability.