Enhancing Photocatalytic Performance by One-Step Vapor Deposition of SnSe/SnSe₂ Composites

Two-dimensional materials and their van der Waals heterostructures offer significant advantages in photoelectrochemical (PEC) photodetectors and water splitting due to their unique physical and chemical properties. In this study, SnSe, SnSe2, and SnSe/SnSe2 composites were successfully synthesized on FTO glass and carbon cloth substrates using a one-step vapor deposition method. Experimental results demonstrate that the SnSe/SnSe2 composite exhibits a high photocurrent density (29.83 μA/cm2) and superior stability compared to individual SnSe and SnSe2. Moreover, benefiting from its efficient light absorption and synergistic charge transfer, the SnSe/SnSe2 composite shows excellent photocatalytic performance, achieving a total hydrogen production of 57.4 μmol/cm2 within 2 h─7.5 times and 5.1 times higher than that of SnSe and SnSe2, respectively. These findings highlight the significant advantages of composite materials in photocatalysis and water splitting applications. Furthermore, this work presents a simple one-step strategy for the preparation of SnSe/SnSe2 on various substrates, providing a solid foundation for future research and practical applications in this field.