Heterostructured Bi₂S₃–Bi₂O₃ Nanosheets with a Built-In Electric Field for Improved Sodium Storage

Constructing novel heterostructures has great potential in tuning the physical/chemical properties of functional materials for electronics, catalysis, as well as energy conversion and storage. In this work, heterostructured Bi 2 S 3 –Bi 2 O 3 nanosheets (BS–BO) have been prepared through an easy water-bath approach. The formation of such unique BS–BO heterostructures was achieved through a controllable thioacetamide-directed surfactant-assisted reaction process. Bi 2 O 3 sheets and Bi 2 S 3 sheets can be also prepared through simply modifying the synthetic recipe. When employed as the sodium-ion battery anode material, the resultant BS–BO displays a reversible capacity of ∼630 mA h g –1 at 100 mA g –1 . In addition, the BS–BO demonstrates improved rate capability and enhanced cycle stability compared to its Bi 2 O 3 sheets and Bi 2 S 3 sheets counterparts. The improved electrochemical performance can be ascribed to the built-in electric field in the BS–BO heterostructure, which effectively facilitates the charge transport. This work would shed light on the construction of novel heterostructures for high-performance sodium-ion batteries and other energy-related devices.