Efficient interfacial charge separation in graphene quantum dots/tin disulfide hybrids for improved photoelectrochemical performance.

Due to their distinctive layered structure, two-dimensional materials facilitate the arrival of photogenerated charges on their surfaces, making them potential candidates for photoelectric catalysis research. In this study, OH-GQDs/SnS₂ composites were effectively fabricated through a simple hydrothermal method. The samples were meticulously analyzed, revealing their morphology, intricate structure, and composition. Additionally, the photoelectrocatalytic performance of the heterojunction was meticulously evaluated. The results demonstrate that OH-GQDs intimately attach to the surface of SnS₂ ultrathin nanosheets, signaling robust interfacial interactions. With the integration of OH-GQDs, the composite exhibits enhanced absorption of visible light, leading to a remarkable improvement in photocatalytic degradation efficiency towards methyl orange, as well as superior photoelectrochemical activity. The heterojunction generates a photocurrent at 0.6V (vs. Ag/AgCl) that is tenfold higher compared to pure SnS₂. By means of Kelvin probe force microscopy (KPFM), an extensive analysis was carried out to scrutinize the surface potential of the OH-GQDs/SnS₂ composite. At the junction, it was noticed that photogenerated electrons migrated from SnS₂ to OH-GQDs, thereby considerably improving the efficiency of electron–hole pair separation. Consequently, this facilitated the improved performance of photocatalysis and photoelectric catalysis. These findings provide important references and effective ways to design efficient graphene quantum-dot photocatalysts. [ABSTRACT FROM AUTHOR]