Aqueous Electrochemical Interfaces
A snapshot of a simulation of an aqueous electrolyte with water molecules omitted for clarity. Electrode atoms are colored corresponding to their partial charge with darker shades of blue or red corresponding to more positive or negative charge.
The electrolysis of water describes the use of electricity to convert liquid water (H2O) into Hydrogen and Oxygen gas. When coupled to a photo-voltaic cell this particular reaction effectively converts solar energy into a clean-burning chemical fuel.
2H2O(l) 
02(g) + 4H+(aq) + 4e- at the anode
4H+(aq) + 4e- 
2H2(g) at the cathode
Although the stoichiometry of the reaction is well known, the reaction mechanism is still poorly understood.
Our current efforts are aimed at developing a better understanding of this process. To do this we use molecular dynamics simulations in a model electrochemical cell. Our simulations makes use of a realistic model of metallic electrodes originally developed by Siepmann and Sprik [1], in which the electrode is maintained at constant electrostatic potential relative to the solution. Our early work with this model focuses on elucidating the solvent structure and fluctuations in the vicinity of the electrodes. We also investigate redox free energies and how they depend on a species position relative to the electrodes. For more information see reference 2 below.
1. J.I. Sipemann and M. Sprik, J. Chem. Phys., 102, 511-524, (1995).
2. A.P. Willard, S.K. Reed, P.A. Madden, and D. Chandler, Faraday Discuss., 141, 432, (2009).
