• S. Velusubhash
• Dr. K. Kalirajan
• Dr. S. Harikengaram
• Dr. R. Vettumperumal
• Dr. R. Murugesan,

In the present work, the combined effect of dopant and capping agent on Zinc sulphide (ZnS) Quantum dots (QDs) has taken for investigation. Simple chemical co- precipitation technique has been employed for preparing the ZnS QDs samples. The transition metal of Nickel ion (Ni2+) is used as a dopant, Urea and thiourea are used as capping agents for preparation of ZnS QDs samples at room temperature. Pure ZnS QDs and Ni2+ ion doped ZnS QDs in different capping agent were characterized by UV-Visible, FTIR, PL, XRD, SEM, EDAX and Electrochemical workstation. The XRD investigations indicated that the prepared undoped and doped ZnS QDs samples with different capping agents are crystalline, with cubic zinc blend structure. ZnS QDs samples exhibits an crystallite size of 1.2 to 1.8 nm. FTIR analysis confirms the inclusion of Ni2+ dopant along with different capping agent such as urea and thiourea into ZnS QDs. UV- Visible analysis showed a broad adsorption band around 293-305 nm. The blue-shift in the absorption spectra and corresponding variation in band gap were also observed. The PL investigations showed narrow and sharp emission band at around 388 nm, 522 nm and 789 nm. Electrochemical analysis was carried out by studying the transition of photogenerated electrons in all the ZnS QDs samples with modified Glassy carbon electrodes (GCE). In addition, the prepared ZnS QDs samples were used as nanophotocatalysts, for photodegradation of Malchite Green (MG) dye. Urea capped Ni2+ doped ZnS QDs act as a better photocatalyst under visible light radiation.

Quantum dots, Dopant, Capping agent, Band gap, Photo catalyst.

"Influence of combined effect of dopant and capping agent on Structural, Optical Electrochemical properties of Zinc Sulphide quantum dots", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 8, page no.1154-1164, August-2018, Available :http://www.jetir.org/papers/JETIR1808472.pdf

"Influence of combined effect of dopant and capping agent on Structural, Optical Electrochemical properties of Zinc Sulphide quantum dots", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 8, page no. pp1154-1164, August-2018, Available at : http://www.jetir.org/papers/JETIR1808472.pdf