Stacked ZnS multilayers of ZnS(en)0.5 hybrids with enhancing photocatalytic performance for H2 production

Abstract

Zinc sulfide hybrids with different stacked ZnS multilayers were prepared using a chemical precipitation method in a solvent mixture of Ethylenediamine:Water:Butanol via two routes - nitrate and acetate salt precursors. The impact of butanol solvent contents (30 and 60 vol%) on the formation of orthorhombic-ZnS(en)0.5 hybrid with different stacking of ZnS layers was comprehensively analyzed using X-ray diffraction, Fourier Transform Infrared, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. Scanning electron microscopy was employed to study the influence of the mixture solvent on particle size and morphology of the resulting ZnS(en)0.5 hybrid micro flakes or nanosheets. The photocatalytic response was evaluated through hydrogen production reactions using low photocatalyst load under UV light irradiation, conducted over four reaction cycles. A significant increase in hydrogen production rate (4.6 and 4.0 times more active) was achieved for the exfoliated ultrathin nanosheet ZnS(en)0.5 hybrid prepared with lower butanol contents from the nitrate and acetate route, respectively. This enhancement was attributed to the reduced size of the nanosheets of stacked ZnS multilayers, which resulted from the incorporation of 30 vol% of butanol during the synthesis. Overall, the findings indicate that the Ethylenediamine:Butanol solvent system plays a crucial role in tuning the degree of ZnS stacking layers, the particle size, and morphology of ZnS(en)0.5 hybrids, leading to improved photocatalytic performance in hydrogen production reactions.