Reactive force field study of the molecular structure of water under thermal and electric effects: Water splitting phenomenon

The molecular structure of water under thermal and electric field effects is determined by using molecular dynamics simulation within a reactive force field and a charge equilibration schema. Focusing the study around the solid and liquid phases, oxygen-oxygen, oxygen-hydrogen and hydrogen-hydrogen radial distribution functions are calculated for several temperatures and applied electric fields. The calculated radial distribution functions signal the conventional solid-liquid and liquid-gas phase transitions of water, including its well known volumetric expansion at the melting point. The temperature driven water splitting phenomenon as well as the diatomic hydrogen formation is clearly observed at the solid and liquid phases of water through the calculated molecular structure. The water splitting behavior and diatomic hydrogen formation is enhanced by the application of homogeneous electric fields with values comparable to those occurring in common electrolysis experimental setups. Additionally, a melting-like process induced by the application of the electric field is observed.