Synthesis and characterization of Fe3+ and Mn2+ doped ZnS quantum dots for photocatalytic applications: effect of 2-mercaptoethanol and chitosan as capping agents

Shravan Pradeep, Sai Raghuram, Mahua Ghosh Chaudhury, Sonal Mazumder, Journal of Nanoscience and Nanotechnology 17 (2) :1125-1132 (2017).
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Abstract

Fe3+ and Mn2+ capped ZnS quantum dots were synthesized using the chemical precipitation method at room temperature in aqueous media. The effect of 2-Mercaptoethanol and Chitosan as capping agents and dopants were investigated using Fourier Transform Infra-Red (FTIR), X-ray Diffraction (XRD), UV-Visible and Field Emission Scanning Electron Microscopy (FESEM) analysis of the nanocrystals. FTIR revealed the presence of respective capping agents and FESEM micrograph identifies the particles as poly-dispersed. TEM images showed agglomerated particles with crystal sized ≈3 nm. Particles were analyzed as cubic structured with peaks indexed at (1 1 1), (2 2 1) and (3 1 1) and an average crystalline size of 2.49±0.06 nm. Blue shift is obtained by both doping agents, and band gap values of ranging from 3.75–4.95 eV were reported. Characterizations suggests 2-mercaptoethanol as better capping agent compared to chitosan and has a greater potential for photocatalytic applications