Template Free Architecture of Hierarchical Nanostructured ZnIn₂S₄ Rose-Like Flowers for Solar Hydrogen Production.

We have demonstrated the controlled synthesis of hierarchical nanostructured ZnIn₂S₄ using a facile template free hydrothermal/solvothermal method. The effect of solvents on the morphology and microstructure of ZnIn₂S₄ has been studied by using water, methanol and ethylene glycol as a solvents. The hierarchical nanostructure, i.e., rose-like morphology composed of very thin (5–6 nm) nanoplates of length ˜1 μm which was obtained in aqueous mediated ZnIn₂S₄. The porous structure (distorted flowers) and agglomerated nanoparticles were obtained using methanol-and ethylene glycol-mediated ZnIn₂S₄. Considering the band gap in the visible region, ZnIn₂S₄ is used as a solar light driven photocatalyst. An ecofriendly photocatalytic process for the conversion of poisonous H₂S into H₂ which is a green unconventional energy source has been demonstrated. The nanostructured ZnIn₂S₄ is employed as a photocatalyst for hydrogen production from H₂S via a solar light-driven eco-friendly approach. The stable photocatalytic activity of hydrogen evolution, i.e., 3964 μmol ⁻¹ was obtained using 0.5 gm of such hierarchical nanostructured ZnIn₂S₄ under visible light irradiation. The unique hierarchical nanostructured ZnIn₂S₄ ternary semiconductor having hexagonal layer is expected to have potential applications in solar cells, LEDs, charge storage, electrochemical recording, thermoelectricity, other prospective electronic and optical devices.