Colloidal Single-Layer Photocatalysts for Methanol-Storable Solar H₂ Fuel

Molecular surfactants are widely used to control low-dimensional morphologies, including 2D nanomaterials in colloidal chemical synthesis, but it is still highly challenging to accurately control single-layer growth for 2D materials. A scalable stacking-hinderable strategy to not only enable exclusive single-layer growth mode for transition metal dichalcogenides (TMDs) selectively sandwiched by surfactant molecules but also retain sandwiched single-layer TMDs' photoredox activities is developed. The single-layer growth mechanism is well explained by theoretical calculation. Three types of single-layer TMDs, including MoS₂, WS₂, and ReS₂, are successfully synthesized and demonstrated in solar H₂ fuel production from hydrogen-stored liquid carrier—methanol. Such H₂ fuel production from single-layer MoS₂ nanosheets is CO_x-free and reliably workable under room temperature and normal pressure with the generation rate reaching ≈617 µmole g⁻¹ h⁻¹ and excellent photoredox endurability. This strategy opens up the feasible avenue to develop methanol-storable solar H₂ fuel with facile chemical rebonding actualized by 2D single-layer photocatalysts.