DFT screening of XSc3H8 (X = K, Rb, Cs) hydrides for sustainable hydrogen and optoelectronic applications

초록

For the first time, DFT investigations were used to examine new hydrides with respect to various physical properties for use in optoelectronics and hydrogen storage. With optimal lattice constants of CsSc3H8 being greater than others owing to ionic radii, the cubic phase structure is characterized by the XSc3H8 (X = K, Rb, and Cs) materials. The mechanical elastic constants and negative formation enthalpy energy indicated that these compounds were mechanically and thermodynamically stable. Analyzing the elastic characteristics revealed that these materials were both rigid and anisotropic. Ionic interaction between atoms was demonstrated by the Cauchy index (Cp), and brittle behavior was validated by Pugh's index (B/G), they are good for storing hydrogen because the materials' ionic bonding nature makes hydrogen bonding sites easier to find, and their brittleness may help expose new surfaces for hydrogen absorption during mechanical cycling. The metallic nature of the present materials was verified by an analysis of their electronic band structures and total density states. Each of these compounds has its dielectric function, conductivity, refractive index, absorption, and loss function calculated, among other optical characteristics. Based on the results, XSc3H8 (X = K, Rb, and Cs) is an excellent optical candidate for use in photovoltaic, optoelectronics, and energy storage. Lastly, CsSc3H8, RbSc3H8, and KSc3H8 were determined to have a gravimetric hydrogen storage capacity of 2.92 wt %, 3.53 wt %, and 4.43 wt %, respectively. The findings indicated that these materials could be used for optoelectronic applications and hydrogen storage.

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