Impact of capping agent on structural and optical properties of ZnS nanoparticles

TL;DR

This study investigates how different capping agent concentrations affect the structural and optical properties of ZnS nanoparticles synthesized via sol-gel, revealing size reduction, band gap variation, and fluorescence behavior.

Contribution

It provides new insights into the influence of sodium dodecyle sulphate capping agent on ZnS nanoparticle properties during synthesis.

Findings

Particle size decreases with higher capping agent concentration

Optical band gaps range from 3.8 eV to 4.4 eV

Fluorescence intensities increase with capping agent concentration

Abstract

Nanocrystalline samples of pristine capped and uncapped zinc sulphide were synthesized via the sol-gel technique. The nanocrystallinity of the samples were confirmed by the X-ray diffraction technique, where size of the particle size decreases with the increasing of mol. concentration (x = 0.00, 0.02, 0.03, 0.04 Mol). of capping agent sodium dodecyle sulphate. The obtained crystallite sizes were found to be in the range 4.6 nm to 2.7 nm respectively. The optical band gaps of the samples were estimated by using ultra-violet visible spectroscopic techniques and the band gap values were in the range 3.8 eV to 4.4 eV. All the samples showed quantum confinement behavior compared to bulk sample. Fluorescence (FL) spectra showed three emission peaks at the emission wavelengths around 434 nm, 520 nm, 545 nm, 628 nm, and 694 nm. The FL intensities were proportional to the concentration of capping agent.