Optimization of ZnS synthesis through the incorporation of monoethanolamine (MEA) for the efficient photocatalytic production of H2

Abstract

The synthesis by precipitation method of a ZnS hybrid photocatalyst functionalized with monoethanolamine in a MEA-water solution for its application in photocatalytic hydrogen production was investigated in this research work. The functionalization of ZnS with MEA as an organic component in the hybrid photocatalyst greatly modified the structural, textural, and optical properties of ZnS. With different MEA ratios in the reaction medium, these properties were enhanced. The specific surface area is augmented up to 150 m²/g, and the hybrid photocatalyst exhibited an optical response in the visible spectrum. Moreover, the crystallite size was affected by the incorporation of the MEA molecule. However, the photocatalytic efficiency is significantly improved due to the role of the MEA molecule in facilitating electron transfer, which favors electron–hole separation and consequently reduces the recombination rate. The most active photocatalyst showed a hydrogen evolution rate of almost 7900 μmol g_cat⁻¹ h⁻¹. The high photocatalytic performance was attributed to its large surface area, crystallite size, and the incorporation of MEA molecules as the organic component in the hybrid photocatalyst.