Janus ZnS nanoparticles: Synthesis and photocatalytic properties

The ball-like ZnS microparticles assembled of nanoparticles with the size of 3-5 nm were synthesized by chemical bath deposition using thiourea as sulfur agent. Their defectiveness was examined by electron paramagnetic resonance (EPR) and high-resolution transmission electron microscopy (HRTEM). Multiple imperfections of ZnS lattice were visualized using HRTEM, where the patterns of the grain boundaries between sphalerite and wurtzite appear the most legible and often. Inherency of such a grain boundary to individual nanoparticle, hence, the Janus morphology of synthesized ZnS nanoparticles, was confirmed using molecular dynamics simulations of their stability. The extremely intense EPR response was obtained, which interpretation assumes the presence of intrinsic electric field arising due to a giant dipole moment across the interface within Janus nanoparticle. The powders of such sedimented ZnS particles exhibited an enhanced photocatalytic activity in reaction of hydroquinone oxidation under visible light irradiation, employing neither alteration of the band gap of ZnS nor any doping of ZnS lattice.

Automated summary

Ball-like ZnS microparticles assembled from nanoparticles were synthesized using thiourea, showing multiple imperfections in the lattice and a Janus morphology. Molecular dynamics simulations confirmed the presence of grain boundaries in individual nanoparticles. The sedimented ZnS particles exhibited enhanced photocatalytic activity under visible light without altering the band gap or doping of the lattice.