Synthesis, Characterization, and Photocatalytic Properties of In2S3, ZnIn2S4, and CdIn2S4 Nanocrystals

A one-pot method has been employed to synthesize the nanocrystals of In2S3, ZnIn2S4, and CdIn2S4. The single-source precursor [In(bipy)(SC{O}Ph)3] has been used for making In2S3 nanocrystals. On the other hand, [Zn(SC{O}Ph)2]·2H2O or [Cd(SC{O}Ph)2]·2H2O was reacted with [In(bipy)(SC{O}Ph)3] and decomposed to make the corresponding ternary metal indium sulfides. The nanocrystals have been characterized by X-ray powder diffraction (XRPD), transmission (TEM) and scanning electron microscopies (SEM), selected area electron diffraction (SAED) patterns, and energy-dispersive X-ray analysis (EDX). Parameters such as temperature, molar ratio of precursor to surfactant, duration of reaction time, and surfactant type were varied to investigate their influence on the morphology and size of nanomaterial. It was found that In2S3 exhibits different morphologies under different reaction conditions whereas the effect of these reactions conditions on the morphological evolution is not very prominent for ZnIn2S4 and CdIn2S4. All the synthesized metal ternary In2S3 showed efficient photocatalytic degradation of dye under ultraviolet (UV) light irradiation. We observed that the degradation of dye is much faster in chloroform than in the aqueous solution as the dispersion of nanoparticles is more homogeneous in chloroform solution. A comparison of the photocatalytic activity of In2S3 with ZnIn2S4 and CdIn2S4 having similar morphology and size shows that the photocatalytic activity of the ternary chalcogenides of In2S3 is considerably enhanced.