RESEARCH ARTICLE Synthesis, characterization and optical property investigation of CdS nanoparticles D.B. Bharti 1 | Avinash V. Bharati 2 | Atul V. Wankhade 3 1 J D College of Engineering and Management and Shree ramdeobaba College of Engineering and Management, Nagpur, India 2 Shree Ramdeobaba College of Engineering and Management, Nagpur, India 3 Visvesvaraya National Institute of Technology, Nagpur, India Correspondence D. B. Bharti, J D College of Engineering and Management, Nagpur, India. Email: datta_bharti@rediffmail.com Abstract Microwave‐assisted routes have attracted much attention for nanoparticle synthe- sis because of minimal solvent use and rapid, high efficiency and controlled mor- phology. Cadmium sulphide (CdS) nanoparticles form the line between bulk and molecular states of materials and show variation in their physical and chemical properties. Cadmium sulphate and thiourea were used as precursors during this synthesis. These are included in the category of practical semiconductor metal sulphides, which are extensively used as catalysts and optical materials. X‐ray diffraction (XRD) patterns confirmed that CdO nanoparticles are crystalline and have a hexagonal phase with crystal sizes that agree with transmission electron microscopy (TEM) data. UV–visible spectroscopy and photoluminescence (PL) spectroscopy were used to evaluate optical properties using band gap energy measurements. KEYWORDS band gap, CdS nanoparticles, microwave‐assisted method, optical property 1 | INTRODUCTION Over the last two decades, nanoscience has infiltrated almost each every field of study. [1,2] The synthesis of metal sulphide nanoparticles has attracted considerable interest [3–5] , therefore many methods have been developed to synthesize CdS nanoparticles. This nanoparticle has special optoelectric properties specific to II-IV semiconductors and has attracted much attention due to its wide band gap. [6,7] How- ever, many of its synthesis techniques have required high tempera- tures and require execution in expensive inert environments. A.D. Mani and colleagues reported an innovative route to synthesize CdS nanoparticles by combustion. [8] T. Torimotom and colleagues synthe- sized CdS nanoparticles using potato starch, and glucose as the capping agents in an environmentally friendly methods. [9] Ajodhya and colleagues studied the antibacterial, photocatalytic activities and fluorescence of CdS nanoparticles. [10] Wang and colleagues synthe- sized CdS nanoparticles using microwave‐assisted and ultrasonic irradiation as an effective method. [11] Vineet Singh and colleagues reported potential applications such as light‐emitting diodes, photode- tectors, electricity‐driven lasers, optoelectronics, photocatalysts and window materials for the hetero‐junction of CdS solar cells. [12,13] In the present study, we report an effective, low‐cost and ecofriendly microwave‐assisted hydrothermal method for the synthesis of CdS nanoparticles at 150°C. These CdS nanoparticles were charac- terized by X‐ray diffraction (XRD), UV–visible spectroscopy, fluores- cence spectroscopy, and TEM and their optical properties were studied. 2 | EXPERIMENTAL 2.1 | Materials All chemicals, cadmium sulphate (CdSO 4 8H 2 O), thiourea ((NH 2 ) 2 CS), tertiary butyl alcohol (C 4 H 9 OH), cyclohexane (C 6 H 12 ), cetyltrimethylammonium bromide (CTAB), ethanol and deionized water were of analytical grade and used without any further purification. 2.2 | Synthesis of CdS nanoparticles A microwave‐assisted hydrothermal method was used to synthesize CdS nanoparticles. [13–15] Here, 5 ml of 5 mmol (NH 2 ) 2 CS, 4 ml t‐ C 4 H 9 OH, 25 ml C 6 H 12 and 0.104 g CTAB were uniformly mixed to Received: 13 May 2018 Revised: 10 September 2018 Accepted: 27 September 2018 DOI: 10.1002/bio.3572 Luminescence. 2018;1–5. © 2018 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/bio 1