Elucidating the adsorption of 2-Mercaptopyridine drug on the aluminum phosphide (Al(12)P(12)) nanocage: A DFT study

Adsorption amplitude of the aluminum phosphide (Al(12)P(12)) nanocage toward the 2-Mercaptopyridine (MCP) drug was herein monitored based on density functional theory (DFT) calculations. The adsorption process through MCP⋅⋅⋅Al(12)P(12) complex in various configurations was elucidated by means of adsorption (E(ads)) energies. According to the energetic affirmations, the Al(12)P(12) nanocage demonstrated potential versatility toward adsorbing the MCP drug within the investigated configurations and exhibited significant negative adsorption energies up to −27.71 kcal/mol. Upon the results of SAPT analysis, the electrostatic forces showed the highest contributions to the overall adsorption process with energetic values up to −74.36 kcal/mol. Concurrently, variations of molecular orbitals distribution along with alterations in the energy gap (E(gap)) and Fermi level (E(FL)) of the studied nanocage were denoted after adsorbing the MCP drug. The favorable impact of water solvent within the MCP⋅⋅⋅Al(12)P(12) complexes was unveiled and confirmed by negative solvation energy (ΔE(solv)) values up to −17.75 kcal/mol. According to thermodynamic parameters, the spontaneous and exothermic natures of the considered adsorption process were proclaimed by negative values of ΔG and ΔH parameters. Significant changes in the IR and Raman peaks, along with the appearance of new peaks, were noticed, confirming the occurrence of the targeted adsorption process. Furthermore, the adsorption features of the MCP drug on the Al(12)N(12) nanocage were elucidated and compared to the Al(12)P(12) analog. The obtained results demonstrated the higher preferability of Al(12)P(12) nanocage than the Al(12)N(12) candidate towards adsorbing the MCP drug without structural distortion.