Experimental Realization and Computational Investigations of B₂S₂ as a New 2D Material with Potential Applications

A new two-dimensional material B₂S₂ has been successfully synthesized for the first time and validated using first-principles calculations, with fundamental properties analyzed in detail. B₂S₂ has a similar structure as transition-metal dichalcogenides (TMDs) such as MoS₂, and the experimentally prepared free-standing B₂S₂ nanosheets show a uniform height profile lower than 1 nm. A thickness-modulated and unique oxidation-level dependent band gap of B₂S₂ is revealed by theoretical calculations, and vibration signatures are determined to offer a practical scheme for the characterization of B₂S₂. It is shown that the functionalized B₂S₂ is able to provide favorable sites for lithium adsorption with low diffusion barriers, and the prepared B₂S₂ shows a wide band photoluminescence response. These findings offer a feasible new and lighter member for the TMD-like 2D material family with potential for various aspects of applications, such as an anode material for Li-ion batteries and electronic and optoelectronic devices.