Fabrication of nanocomposite polyaniline zirconium(IV) silicophosphate for photocatalytic and antimicrobial activity Deepak Pathania a , Gaurav Sharma a,⇑ , Amit Kumar a,b , N.C. Kothiyal c a School of Chemistry, Shoolini University, Solan 173212, Himachal Pradesh, India b Department of Chemistry, Himachal Pradesh University, Summer Hill, Shimla, India c Department of Chemistry, National Institute of Technology, Jalandhar, Punjab, India article info Article history: Received 8 October 2013 Received in revised form 19 November 2013 Accepted 20 November 2013 Available online 27 November 2013 Keywords: Nanocomposite Ion exchanger Photocatalysis Antimicrobial abstract Polyaniline zirconium(IV) silicophosphate (PANI–ZSP) nanocomposite ion exchanger was prepared using sol–gel method by mixing polyaniline (PANI) gel into the inorganic precipitates of zirconium(IV) silico- phosphate (ZSP). The nanocomposite ion exchanger was characterized by techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The thermal stability, elution behaviour, concentration behaviour and acid-base properties of nanocomposite ion exchanger were investigated. The study revealed that PANI–ZSP nancomposite material exhibit higher ion exchange capacity (1.05 meq/g) com- pared to its inorganic counterpart ZSP (0.65 meq/g). The PANI–ZSP nanocomposite ion exchanger was thermally stable and retained about 47.16% of ion exchange capacity up to 300 °C. The PANI–ZSP nano- composite ion exchanger was utilized as photocatalyst for remediation of methylene blue dye from water. A degradation efficiency of 82% was achieved in two hours of exposure. Nanocomposite ion exchanger has been successfully used as antibacterial agent against Escherichia coli (E. coli). Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction The unprecedented opportunities in material designing have fuelled rapid development in synthesis of nanostructured compos- ite materials, by using organic polymer and inorganic fillers. Or- ganic–inorganic composites with nanoscale dimensions are of growing interest because of their multifunctionality, and numer- ous potential applications such as enhancement of conductivity [1,2], toughness [3] optical activity [4] catalytic activity [5] and chemical selectivity [6]. Numerous composite ion exchange mate- rials have been synthesized in recent year by the combination of organic polymeric species and inorganic groups. The composite ion exchange materials in nanorange have been found vast applica- bility in diverse fields such as drug delivery, photocatalysis, chro- matography, ion selective electrodes and environmental remediation [7–13]. As inorganic synthetic ion exchangers are costly, non-reproduc- ible and are inefficient to treat large volume of waste effluents [14]. On the other hand, the organic ion exchangers have less thermal and radiation stability [15]. However, on macro scale there utility for wastewater treatment is on limited scale. In order to obtain a combination of these advantages associated with polymeric and inorganic materials as ion-exchangers, attempts have been made to develop polymeric–inorganic composite ion-exchangers by incorporation of organic monomers in the inorganic matrix [16]. Conducting polymers fetch conductance through a conjugated bond system along the polymer backbone. They are synthesized through either chemical oxidation of the monomer or electrochem- ical oxidation of the monomers as pyrrole, aniline, etc. [17]. Among conducting polymers polyaniline has proved to be most promising constituent of multifunctional hybrid nano-materials. Polyaniline based composite materials have received great attention since its rediscovery due to its wide range of application such as actuators, electrochromic and photovoltaic devices, secondary batteries, fuel cells, supercapacitors, ionic sensors, biosensors, electro catalysis and corrosion protection [18]. In order to improve functions of PANI, preparation of its composites has attracted a great deal of attention. Composites of PANI with various moieties which can be metals, metalloids, non-metals, inorganic and organic compounds, biopolymers, etc., were prepared and characterized by numerous researchers world- wide. A lot of research is done on synthesis of PANI/metal, PANI/ metalloid, PANI/non-metal composites and have been exploited for various electrolytic, photo-catalytic and sensing applications [19,20]. Semiconductor and metal-based nanostructures have been extensively used because of tuneable optical properties for photo- chemical applications [21]. However, conjugated polyenes as PANI may act as sensitizers and also modify physical and chemical prop- erties of metal based materials. PANI has been a popular part of many hybrid ion exchangers. A little work has been done on 0925-8388/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jallcom.2013.11.133 ⇑ Corresponding author. Tel.: +91 9418807170. E-mail address: gaurav8777@gmail.com (G. Sharma). Journal of Alloys and Compounds 588 (2014) 668–675 Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: www.elsevier.com/locate/jalcom