A DFT investigation of nanomaterial BN/WSe₂ heterostructure: A potential cadmium adsorbent

Cadmium (Cd) is vital in industry, but its toxicity poses a threat to the environment. Hence, it is imperative to investigate reusable cadmium adsorption materials at ambient temperature. Boron nitride (BN) is widely used due to its exceptional specific surface area and tungsten diselenide (WSe₂) with narrow bandgap can effectively improve the ability to absorb Cd. Therefore, in this study, the adsorption performance of cadmium by BN/WSe₂ heterostructure was investigated by first principles calculation. The analyses indicate that BN/WSe₂ is structurally stable and thermodynamically stable at 300 K. Furthermore, compared to intrinsic BN and WSe₂, the band gap of BN/WSe₂ has been reduced to 1.4405 eV, which enhances electron transition capabilities, increases interaction with Cd ions, and improves overall adsorption capacity. Notably, in this study, the maximum adsorption energy of BN/WSe₂ heterostructure can reach -0.451 eV while exhibiting favorable desorption characteristics. Moreover, the research shows that the interlayer diffusion barrier within BN/WSe₂ significantly exceeds that of surface diffusion barriers, indicating superior cadmium surface adsorption capacity. Consequently, BN/WSe₂ is expected to be an excellent cadmium adsorption material, which provides innovative solutions for addressing Cd pollution.