Highly efficient photoelectrochemical water oxidation enabled by enhanced interfacial interaction in 2D/1D In2S3@Bi2S3 heterostructures†
Abstract
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 a two-step solvothermal in situ growth. Theoretical calculations demonstrate that In2S3 nanosheets and Bi2S3 nanorods are integrated together through the vdW interaction. Through theoretical calculations and experiments, the results confirm that the surface potential of Bi2S3 is higher than that of In2S3, implying that the free electrons will flow from Bi2S3 to In2S3 when the two semiconductors come into contact, leading to electron and hole accumulation at the In2S3 and Bi2S3 surface. This redistribution of charges will induce an outward vector of a built-in electric field at the In2S3@Bi2S3 interface (from Bi2S3 to In2S3), thereby improving hole transfer to In2S3 and electron transfer to Bi2S3. The advanced heterostructure aids in shortening the photogenerated electrons' transport time (14 μs), promoting the electron–hole separation, and presents a 13.3-fold enhancement in photocurrent density when compared to In2S3.