Phase-Controlled Synthesis of Single-Crystalline Tin Sulfide Nanosheets for PEC Water Oxidation

Precise control over the stoichiometry and phase of tin sulfide (SnSx) nanomaterials is critical for their potential applications in energy conversion and storage devices, which remains challenging. Here, we report a precursor-mediated colloidal method to achieve phase-controlled synthesis of single-crystalline (SC) SnSx nanosheets. By employing Sn(acac)2Cl2/S and SnCl2·2H2O/1-DDT as precursors, hexagonal SC SnS2 nanosheets and orthorhombic SC SnS nanosheets were successfully synthesized, respectively. The photoelectrochemical (PEC) performance of both samples as photoanodes for water oxidation was further studied. The SC SnS2 nanosheet photoanode achieves a PEC performance of 1500 μA cm–2 at 1.23 VRHE with a half-cell solar-to-hydrogen conversion efficiency of 0.85%, outperforming the SC SnS nanosheet photoanodes. Meanwhile, this precursor-mediated method can be readily extended to the phase- and stoichiometry-controlled synthesis of other 2D nanomaterials, which hold great potential in photocatalysis and photoelectrochemical applications.