Highly efficient photoelectrochemical water oxidation enabled by enhanced interfacial interaction in 2D/1D In2S3@Bi2S3 heterostructures

摘要： Van der Waals (vdW) heterostructures have received tremendous attention in low dimensional semiconductors due to interfacial surface reconstruction and electronic coupling effects. Here, we report mixed-dimensional 2D/1D In2S3@Bi2S3 heterostructures synthesized via two-step solvothermal in-situ growth. Theoretical calculations demonstrate In2S3 nanosheets and Bi2S3 nanorods are integrated together through the vdW interaction. Through theoretical calculations and experiment, the results confirm the surface potential of Bi2S3 is higher than In2S3, implying the free electrons will flow from Bi2S3 to In2S3 when the two semiconductors contact, leading to electron’s and hole’s accumulation at In2S3 and Bi2S3 surface. This redistribution of charges will induce an outward vector of built-in electric field at the In2S3@Bi2S3 interface (from Bi2S3 to In2S3), thereby improving hole’s transfer to In2S3 and electron’s transfer to Bi2S3. The advanced heterostructure aids in shortening the photogenerated electrons’ transport time (14 μs), promoting the electron-hole’s separation, and presents 13.3-fold enhancement in photocurrent density when compared to In2S3.