Architecture of rose and hollow marigold-like ZnIn2S4 flowers: structural, optical and photocatalytic study

In the present investigation, a surfactant-assisted hydrothermal route has been employed to design self-assembled rose and hollow marigold-like ZnIn2S4 flowers. In the absence of the surfactant, uniform (∼3–5 μm) marigold-like flowers are observed. The self-alignment of the transparent petals (∼3–5 nm thick with a length of ∼25–100 nm) leads to the formation of hollow marigold-like flowers, for which a plausible growth mechanism has also been proposed. Moreover, DEA assisted ZnIn2S4 demonstrates a rose flower-like via self assembly of hexagonal nanoplates. Structural and optical characterization shows the existence of hexagonal structures with a band gap in the range of ∼2.4–2.6 eV. Considering the ideal band gap in the visible region, we have used such unique nanostructured self assemblies of ZnIn2S4 as photocatalysts and demonstrated visible light-driven photocatalytic production of clean hydrogen by toxic hydrogen sulphide, which is abundantly available as a waste gas from oil refineries (15–20%). We believe that continuous efforts in this direction may open up new insights into the design of controllable nanostructures and their potential applications in advanced fields.