Colloids and Surfaces A: Physicochem. Eng. Aspects 481 (2015) 269–275 Contents lists available at ScienceDirect Colloids and Surfaces A: Physicochemical and Engineering Aspects journa l h om epage: www.elsevier.com/locate/colsurfa Synthesis of zincblende CuInS 2 and Fe-substituted CuInS 2 by the reaction of binary colloids Meenakshi Gusain, Prashant Kumar, Sitharaman Uma, Rajamani Nagarajan ∗ Materials Chemistry Group, Department of Chemistry, University of Delhi, Delhi 110 007, India h i g h l i g h t s • Binary colloids of Cu–S and In–S in ethyleneglycol reacted to yield CuInS 2 . • CuInS 2 exhibited zincblende arrange- ment. • Following this success, higher con- centrations of iron substituted for indium. • This soft chemical process is simple, robust and rapid. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 18 March 2015 Received in revised form 25 May 2015 Accepted 27 May 2015 Available online 1 June 2015 Keywords: Copper indium sulphide Colloids Reactivity Polymorph TEM Electron microscopy SAED pattern a b s t r a c t Colloidal suspension of binary sulfides of copper and indium were generated by the reaction of CuCl and In 2 (SO 4 ) 3 with thiourea independently in ethyleneglycol. The colloids were identified to be Cu 9 S 5 and a mixture of InS and In 2 S 3 from the TEM-SAED measurements. They were reacted to yield phase pure CuInS 2 in zincblende arrangement as endorsed by the powder X-ray diffraction pattern, TEM-SAED, lattice fringe measurements and Raman spectroscopy measurements. Optical band gap of zincblende CuInS 2 was measured using UV–visible spectroscopy. In the photoluminescence spectrum, a strong emission centred at around 750 nm was observed on exciting the sample with  = 500 nm. Following this success, quaternary composition containing Cu, In, Fe and S in zincblende arrangement has been synthesized and characterized. Band gap of iron substituted samples was estimated to be 1.07 eV. It showed paramagnetic behaviour at room temperature suggesting its use as opto-magnetic material. While cubic CIS degraded methylene blue dye solution under visible light radiation, iron substituted sample did not promote this reaction. © 2015 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +91-11-27662650. E-mail address: rnagarajan@chemistry.du.ac.in (R. Nagarajan). 1. Introduction Owing to the rich heritage as ores, tuneable semiconducting property and structural diversity, copper containing I–III–VI 2 type compounds have always been a focus of immense interest among http://dx.doi.org/10.1016/j.colsurfa.2015.05.027 0927-7757/© 2015 Elsevier B.V. All rights reserved.