Jiyuan Guo

Stability and tunable optoelectronic properties of Janus Ga ₂ XTe (X = S, Se) monolayers under hydrostatic pressures.

Room-temperature Na-S (RT Na-S) batteries are capable of attaining a theoretical energy density as great as 1274 Wh/kg and functioning within a relatively mild temperature range of 25-60 ℃. Nevertheless, the inferior oxidation-reduction kinetics and polysulfide shuttle effect in Na-S batteries significantly impede their practical applications. Consequently, the development of high-performance anchoring materials capable of both immobilizing polysulfides and catalyzing their conversion is therefore critical. Herein, first-principles calculations were utilized to assess the potential of a novel 2D material, C5N3, serving as a multifunctional host for sodium polysulfides in Na-S batteries. Through comprehensive analyses, including structural optimization, charge transfer evaluation, and van der Waals corrections, it is revealed that C5N3 exhibits moderate adsorption energies toward high-order sodium polysulfides (Na2Sx, x=8,6,4), with the values falling in the range of 1.543 to 1.812 eV, substantially larger than those of conventional electrolytes. This robust binding effectively suppresses polysulfide dissolution. Furthermore, the energy barrier of the rate-limiting step in the sodium polysulfide reduction reaction (SRR) is determined to be 1.168 eV. Notably, applying an external electric field reduces this barrier to 0.533 eV, thereby substantially expediting the catalytic breakdown of low-order polysulfides (Na2Sx, x=2,1). These findings collectively demonstrate that electric-field-modulated C5N3 shows promise as an advanced anchoring material for high-performance RT Na-S batteries.

Traditional hydrogen storage methods rely on high-pressure or cryogenic conditions, which limit their practical applicability. The emergence of 2D materials has opened new avenues for physical adsorption-based hydrogen storage. Herein, we systematically investigate the hydrogen storage performance and environmental adaptability of 2D inorganic biphenylene (I-BPN) using first-principles and semiempirical calculations. Key results demonstrate that the pristine I-BPN monolayer exhibits excellent mechanical and thermodynamic stability, with hydrogen adsorption energies falling within the range characteristic of physisorption. It achieves a gravimetric hydrogen storage density of 10.78 wt % and a volumetric density of 132.37 g/L, competitive with state-of-the-art 2D hydrogen storage materials. Moreover, the application of an external electric field enhances H₂ adsorption, indicating a tunable storage capacity. The semiempirical method is employed to investigate the binding and release capabilities of H₂ molecules within the operational temperature and pressure parameters. It is found that the unmodified I-BPN monolayer possesses a remarkable reversible hydrogen storage capacity of 10.02 wt %, outperforming many other 2D materials with the same elemental compositions or similar structures. These findings highlight that the pristine I-BPN monolayer is a promising candidate for low-cost, high-efficiency hydrogen storage, offering the potential for advancing practical hydrogen energy applications.