Effect of external electric fields on sulfur dioxide–water systems

The effect of external electric fields on sulfur dioxide (SO₂) is often neglected, and it is an important source of environmental pollution. We use density functional theory (DFT) to obtain the cluster structures and intermolecular binding energies of SO₂–(H₂O)_n in the presence of an external electric field and molecular dynamics (MD) to calculate the solutions’ properties. The results show that the electric field reduces the binding energy between SO₂ and water, and inhibits the diffusion of SO₂. The positive shift of binding energy and solvation free energy indicates that the solubility of sulfur dioxide decreases under electric field, which is in agreement with our experimental results. The results are helpful to the study of the interaction between sulfur dioxide and water in the strong electric field near the high-voltage line.