400 Int. J. Nanotechnol., Vol. 18, Nos. 5/6/7/8, 2021 Copyright © 2021 Inderscience Enterprises Ltd. Solvent composition induced structure control of cadmium sulphide nanoparticles and investigations on photocatalytic degradation of methylene blue Aravindan Natarajan*, Mohanraj Shanmuganathan, Ezhilan Jayabal and Venkatesan Rangarajan Advanced Materials Research Lab, Department of Chemistry, Pondicherry University, R.V. Nagar, Kalapet, Puducherry 605 014, India Email: aravindann@chempu.ac.in Email: mas019816@gmail.com Email: ezhil2020@gmail.com Email: venkatesanr.che@pondiuni.edu.in *Corresponding author Abstract: The structural regulation of nanoparticles is a challenging task without any structure determining agents such as templates, surfactants, etc. In the present study, the structure of cadmium sulphide nanoparticles (CdS NPs) has been effortlessly changed from hexagonal to face centred cubic structure under solvothermal conditions by facile volume ratio adjustment of the solvents (water and ethanol). The various CdS NPs prepared have been investigated using different characterisation techniques and their structure, size and morphology vary with respect to the solvent composition. Furthermore, the photocatalytic performance of CdS NPs has been investigated using Methylene Blue (MB) as model organic pollutant. It has been observed that the photocatalytic degradation efficiency of MB is significantly influenced by the structure of CdS NPs. Keywords: cadmium sulphide; nanoparticles; photocatalysts; methylene blue; dye degradation; mixed solvent; semiconductor; structure control; cubic phase; hexagonal phase. Reference to this paper should be made as follows: Natarajan, A., Shanmuganathan, M., Jayabal, E. and Rangarajan, V. (2021) ‘Solvent composition induced structure control of cadmium sulphide nanoparticles and investigations on photocatalytic degradation of methylene blue’, Int. J. Nanotechnol., Vol. 18, Nos. 5/6/7/8, pp.400–413. Biographical notes: Aravindan Natarajan is currently a post-doctoral research fellow in the Department of Chemistry, Pondicherry University under the prestigious UGC-Dr. D.S. Kothari post-doctoral research fellowship with significant experience in electrochemistry and photochemistry. Mohanraj Shanmuganathan is currently a Master’s student in the Department of Chemistry, Pondicherry University. His research interests include materials chemistry and photocatalysts.