Vol.:(0123456789) 1 3 J Mater Sci: Mater Electron DOI 10.1007/s10854-017-6805-x Facile synthesis of tungsten trioxide 3D architectures by a simple chemical solution route and photodegradation of Rhodamine B: structural, thermal, optical and impedance studies Ayaz Arif Khan 1  · Muhammad Qadeer Khan 1  · Mazhar Iqbal 1  · Adeel Younas Abid 1  · Abdul Rauf Khan 1  · Yousaf Iqbal 1  · Rashid Mahmood 2  · M. Nasir Khan 3   Received: 28 December 2016 / Accepted: 20 March 2017 © Springer Science+Business Media New York 2017 applications as photo-catalysts, transparent conducting electrodes, electrochromic and sensor devices. 1 Introduction Nano-crystalline transition metal oxides constitute most likely one of the interesting class of materials possessing a diversity of exciting properties in the meadow of electro- chromic, sensors and magnetic devices [1]. The structural and electronic properties of these oxides are infuenced mostly by grain size.[2] Currently, WO 3 low dimensional structures have attracted considerable interest since its frst announcement on electrochromism in 1969 [3]. WO 3 as an electrochromic material reveals good cyclic immov- ability and a high coloration competence as compared to other metal oxides [4]. These nanostructures are promising because of their unique properties including high struc- tural elasticity [5], tunable optical, photo catalytic behavior [6, 7] and gas sensing properties [8]. These features make WO 3 as a suitable candidate for application in smart win- dow, information exhibitor and variable refectance mirrors [6, 9]. It is well known that the grain size and morphology of the materials play a decisive role in fne-tuning their physical and chemical properties. The morphology strongly depends on the synthesis route and condition. In recent times, hierarchical self-assembly of nano-sized building blocks with an assortment of geometrical features, includ- ing, wires, nanosheets, nanotubes [10–12] have gathered incredible attention because of their intrinsic character which may ofer a great possibility to explore their novel properties [13–17]. Much efort has been made to synthe- sized low dimensional nanostructures of tungsten oxide [18, 19]. However, these structures are generally obtained at high temperature and under extensive reaction time. It Abstract A facile chemical precipitation method for slab and fower like WO 3 microstructure having three-dimen- sional (3D) architecture is reported. The as-prepared WO 3 powder specimens were characterized by X-ray difrac- tion (XRD) combined with Rietveld refnements, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy and UV–vis spectroscopy. SEM and XRD results revealed that the hierarchical WO 3 microstructures with uniform fower-like morphology are congregated by number of interleaving nanosheets which have thickness of 150–180 nm and are crystallized in a single monoclinic WO 3 phase. Thermo-gravimetric analysis shows a major weight loss of 8% due to evaporation of adsorbed water. The impedance spectroscopy of compact WO 3 pellets showed that all samples were semiconducting with a min- ute diference in electrical properties. The photo-catalytic activity of the as-prepared WO 3 samples was evaluated by the degradation of Rhodamine B (RhB) under ultra-violet light irradiation. The results showed that 3D hierarchical architectures exhibits high photo-catalytic efciency com- pared with the slab like structure due to their porous hier- archical structures. The optical band gap energy of slab like structure is found to be lowered compared to fower-like WO 3 structures. These tunable optical and transport fea- tures allow the development of new materials for potential * Ayaz Arif Khan ayazbinarif@hotmail.com 1 Department of Physics, University of Azad Jammu & Kashmir, Muzafarabad 13100, Pakistan 2 Department of Chemistry, University of Azad Jammu & Kashmir, Muzafarabad 13100, Pakistan 3 Physics Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad 45650, Pakistan