Novel synthesis of silver nanoparticles using 2,3,5,6-tetrakis-(morpholinomethyl) hydroquinone as reducing agent P. Manivel a , A. Balamurugan a , N. Ponpandian a , D. Mangalaraj a , C. Viswanathan a,b,⇑ a Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046, Tamilnadu, India b DRDO-BU-Center for Life Science, Physics Division, Bharathiar University, Coimbatore 641046, Tamilnadu, India article info Article history: Received 22 January 2012 Received in revised form 19 March 2012 Accepted 25 March 2012 Available online 6 April 2012 Keywords: TMMH Nanoparticles Reducing agent FTIR Organic Crystalline size abstract 2,3,5,6-Tetrakis-(morpholinomethyl) hydroquinone (TMMH) was used as a reducing agent to synthesize spherical shaped silver nanoparticles in water–ethanol medium without using any stabilizing and capping agents. The reducing agent TMMH is prepared by Mannich-type reaction method and 1 H NMR, 13 C NMR and FT-IR spectroscopy techniques were used to characterize the compound (TMMH). The nature of bonding, structural and optical properties of the final product were analyzed using different techniques such as UV–Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The interaction between silver and reducing agent was confirmed by using FTIR analysis. The final product obtained showed higher crystallinity with cubic structure and an average crystalline size of about 20 nm. The results revealed that it is possible to syn- thesize crystalline Ag nanoparticles using organic compound as reducing agent. Ó 2012 Elsevier B.V. All rights reserved. Introduction Nanoparticles are used, due to their potential applications in various fields like optical device, chemical sensor, bimolecular sensor and DNA detection [1]. Among various metals, silver nano- particles are an interesting one because of their size and shape dependent optical properties which render them very useful for technical applications [2]. In particular, there is a remarkable inter- est to produce silver nanoparticles dispersion at large scale [3–4]. Several methods have been reported for the synthesis of silver nanoparticles, including chemical reduction in aqueous solution with or without stabilizing agents [5]. Thermal decomposition in organic solvents [6], chemical and photo reduction in reverse micelles [7] and microwave assistance [8], are some of the factors for the formation of silver nanoparticles. Most of the researchers previously described the stable silver dispersion only at relatively low concentrations of metal. Hence, they are not suitable for large-scale production [9]. The simplest, cost effective and the most commonly used bulk-solution synthetic method for metal nanoparticles is the chemical reduction of metal salts [10]. In fact, production of nanoscale metal silver particles with different mor- phologies and sizes using chemical reduction of silver salts has been reported [11,12]. The effective method to generate silver nanoparticles in narrow size distribution of aqueous medium is achieved by the reduction method using citrate of sodium [13]. Other reducing agents that have been used are ascorbic acid, hydrazine hydrate and sodium dodecyl sulfate. In fact, formation of nanosized silver particles with different morphologies and sizes using chemical reduction of silver salts has been reported [12]. A mixture of hydrazine hydrate and citrate of sodium as a reducing agent in the isolation of silver nano- particles has been reported by Guzman et al. [14]. Tripathy and Yu [15] reported the synthesis of x-mercaptoundecanoic acid gener- ated silver nanoparticles. The nanoparticles were also obtained by chemical reduction of AgNO 3 in ethanol, using triethylenetetra- mine as surfactant [16]. In this method control of the size of the nanoparticles has been achieved by regulating the ratio of metal chloride to the organic reagent. Recently gold nanoparticles were obtained by 2,3,5,6-tetrakis-(morpholinomethyl) hydroquinone as reducing agent [17]. The above approach is well enough to jus- tify our effort to report a new and effective reducing agent for the preparation of silver nanoparticles. In the present work we have made an attempt to synthesize the silver nanoparticles using TMMH as reducing agent. The as-synthe- sized compound (TMMH) after purification was used to synthesize final silver nanoparticles. The secondary hydroxyl groups and nitrogen of TMMH compound have been used for the reduction of AgNO 3 . This approach is a simple, cost-effective, stable for long time, reproducible and previously unexploited method. We found that the size of nanoparticles can be modulated by varying the 1386-1425/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2012.03.081 ⇑ Corresponding author at: Department of Nanoscience and Technology, Bha- rathiar University, Coimbatore 641046, Tamilnadu, India. Tel.: +91 422 2428422. E-mail address: viswanathan@buc.edu.in (C. Viswanathan). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 95 (2012) 305–309 Contents lists available at SciVerse ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa