Surface Analysis of Sulfur Coated Electrides for Enhanced Stability (2024)

Undergraduate: Jackson Sweet

Faculty Advisor: Scott Warren
Department: Chemistry

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Layered electrides are an emerging class of inorganic, crystalline materials that possess bare electrons in place of anions in their crystal lattice. This class of materials possesses a low work function, high anisotropic conductivity, and high energy electrons; however, due to these high energy electrons, electrides are unstable and rapidly degrade in the presence of oxygen. To prevent the degradation of Y2C, a layered electride, we proposed using a surface coating of sulfur to stabilize the material. X-Ray diffraction was used to demonstrate the efficiency of a sulfur layer in preventing the oxidation of Y2C. Previously, vapor phase deposition was used to deposit the sulfur layer onto the surface of electrides. Unfortunately, this method still allowed some oxygen to intercalate resulting in a degraded electride. To produce the sulfur layer without degrading the material, we grinded Y2C under liquid sulfur and then soaked the sulfur-coated system to reduce the thickness of the outer layer. Using energy dispersive spectroscopy of the vapor phase deposition method versus the grinding method, we have demonstrated that the presence of oxygen is significantly reduced by the grinding method. By fine tuning the parameters of the experiment such as temperature, annealing time, and soaking time, the thickness and properties of the sulfur layer can be controlled more easily by the grinding method. These tuned materials can be used in a variety of batteries, optical devices, catalysts, or capacitors.