Contact value relations and density functional theory for the electrical double layer |
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| Authors: | Whasington Silvestre-Alcantara Lutful Bari Bhuiyan Jian Jiang Jianzhong Wu Douglas Henderson |
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| Institution: | 1. Laboratory of Theoretical Physics, Department of Physics, Faculty of Natural Sciences, University of Puerto Rico, San Juan, Puerto Rico, USA;2. Department of Chemical and Environmental Engineering and Department of Mathematics, University of California, Riverside, CA, USA;3. Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA |
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| Abstract: | The recently developed contact-corrected density functional theory is applied to an electric double layer containing a valence and size symmetric electrolyte. The restricted primitive model is used to describe the electrolyte, and a non-polarisable, smooth, planar, uniformly charged hard surface is used to model the electrode. Comparison with Monte Carlo simulation results for this system shows that the theory satisfies the first contact value relation in line with the premise of the approach. Additionally, the theory is found to satisfy the semi-empirical second contact value relation quite closely. This is a welcome result, since no reference is made to this second relation nor is the relation used in the theoretical development. The second contact relation is closely related to the anomalous positive temperature derivative of the double layer capacitance at low temperature, low ion concentration, and low electrode charge, and indeed, the contact-corrected density functional theory predicts this effect. |
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| Keywords: | planar electric double layer Monte Carlo simulation density functional theory and contact relations capacitance anomaly |
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