A Computational Investigation of Bi₂MO₄Cl (M = Y, La and Bi) as Thermoelectric Materials

<br/>In the process of primary energy consumption, a large amount of waste heat is generated. Thermoelectric materials (TEs) can convert waste heat energy into electric energy, which is crucial to solving the current energy crisis and mitigating global warming. In general, the performance of TEs can be determined by the dimensionless figure of merit, <i>ZT</i>, that is evaluated from its electronic and thermal properties. However, it is difficult to maximise <i>ZT</i> due to the interaction between different parameters.<br/><br/>In recent years, mixed anionic oxides have shown great potential in the field of TEs.^1-3 Recently, the mixed anionic oxides Bi₂MO₄Cl (M = Y, La and Bi) was shown to exhibit excellent stability in photocatalytic water oxidation reactions,⁴ but their thermoelectric properties have not been explored. We postulated that this quaternary structure with heavy elements will lead to a low lattice thermal conductivity, and they can be synthesised at a relatively high temperature, thus can maintain stability at high temperatures, so we performed density functional theory (DFT) calculations to study the thermoelectric performance of Bi₂MO₄Cl (M = Y, La and Bi). Our results showed that Bi₂MO₄Cl (M = Y, La and Bi) belongs to p-type TEs and exhibits an average ZT of about 1 at 1000 K.<br/><br/><b>References</b><br/>1 M. Einhorn, B. A. D. Williamson and D. O. Scanlon, <i>J. Mater. Chem. A</i>, 2020, <b>8</b>, 7914-7924.<br/>2 K. Brlec, K. B. Spooner, J. M. Skelton and D. O. Scanlon, <i>J. Mater. Chem. A</i>, 2022, <b>10</b>, 16813-16824.<br/>3 W. Rahim, J. M. Skelton and D. O. Scanlon, <i>J. Mater. Chem. A</i>, 2021, <b>9</b>, 20417-20435.<br/>4 A. Nakada, D. Kato, R. Nelson, H. Takahira, M. Yabuuchi, M. Higashi, H. Suzuki, M. Kirsanova, N. Kakudou, C. Tassel; et al., <i>J. Am. Chem. Soc.</i>, 2021, <b>143</b>, 2491-2499.