Azhar et al. / Malaysian Journal of Fundamental and Applied Sciences Vol. 14, No. 3 (2018) 397-402 397 Significant effect of concentration ratio in synthesizing titania nanoflowers (TNF) powder via facile hydrothermal method Faiz Hafeez Azhar a , Zawati Harun a,* , Muhamad Zaini Yunos a , Azlinorazia Ahmad a , Siti Hajar Mohd Akhair a , Raja Adibah Raja Ahmad a , Abdul Qaiyyum Abd Rashid a , Rosniza Hussin b , Siti Aida Ibrahim b , Mohd Khairul Ahmad c a Intergrated Material and Process, Advanced Manufacturing and Materials Centre (AMMC), Institute Integrated Engineering (IIE), Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia. b Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia c Microelectronic and Nanotechnology – Shamsudin Research Centre (MiNT-SRC), Institute Integrated Engineering (IIE), Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia * Corresponding author: zawati@uthm.edu.my Article history Submitted 12 June 2018 Revised 27 June 2018 Accepted 16 July 2018 Published Online 3 September 2018 Abstract The significant effect of titanium butoxide and hydrochloric acid (TBut/HCl) concentration ratio in synthesizing titania nanoflowers (TNF) towards powder morphologies, crystallographic phases, surface area and band gap were investigated. Various synthesized titania nanostructure were prepared via facile hydrothermal method using titanium butoxide and hydrochloric acid as a mixing composition. The morphologies of synthesizing titania powder were analyzed by using FE-SEM to observe the shape and geometry of the synthesized powder. XRD was used to determine the crystallographic phases of synthesized powder at 2θ angles of 25° to 75°. Each sample was then investigated under BET analyzer to observe the particle surface area and UV-Vis analyzer to determine the band gap. The results demonstrated that the concentration of TBut/HCl ratio gave a very significant effect in transforming the mixing solution into geometrical shape of microspheres, nanoflowers and nanorods of titania as increasing the ratio. At TN0.5, the synthesized powder was clearly showing a circle geometrical shape of particles. The shape was suddenly changed into a round nanoflowers form consist of tiny nanorods at TN1. At TN1.5, the powder morphology shows the nanoflowers started to form in an irregular pattern. As the concentration ratio increased, the nanoflowers form disappeared and nanorods begin to clump. In addition, all synthesized powder was in rutile phases guided by XRD peaks and the band gap value reported from previous works. The particle surface area was also different for each sample since the geometrical shape of powder was changed by increasing the concentration (TBut/HCl) ratio. Thus, concentration ratio of the mixing composition plays a major role in transforming the overall morphologies and structures of hydrothermal synthesis titania particles. Keywords: Titania nanoflower (TNF), titanium dioxide, nanostructure, titanium butoxide, hydrothermal method © 2018 Penerbit UTM Press. All rights reserved INTRODUCTION Nanoparticles Titanium dioxde (TiO2) is well known inorganic material which is commonly used for oxide semiconductor materials due to their unique properties of strong oxidizing power, non-toxic in nature, biological and structure stability, easy handling and low cost material (Byranvand et al., 2013; Karkare, 2014; Di Paola et al., 2013). Until recently, the nanostructured of TiO2 such as nanorods, nanotubes and nanoflowers was widely investigated due to its excellent improvement in various applications such as photocatalytic, solar energy conversion, paint, cosmetics, textiles and photovoltaics (Ahmad & Murakami, 2012; Mcnulty, 2008; Theivasanthi & Alagar, 2013). Many method has been introduced and proposed to prepare and modify the nanostructure of TiO2 powder, such as solvothermal method (Yang & Gao, 2006), direct oxidation method (Sun et al., 2013), chemical vapor deposition (Qu et al., 2013), electrodeposition (Mali et al., 2012), sonochemical method (Prabhu & Poulose, 2012), microwave method (Roy, 2013), and hydrothermal method (Sekino, 2010; Safarpour et al., 2015; Xu et al., 2012) The hydrothermal method is known as the most cost effective methods to synthesize the TiO2 nanostructured powders. Generally, synthesis using hydrothermal can be described as a process of growing a single crystal from an aqueous solution in an autoclave at high temperature followed by applying pressure parameter (Abdullahi et al., 2017; Byrappa & Yoshimura, 2008). By using this simple approach, the morphologies or the structure of the semiconductor materials can be controlled by several variables such as precursor (Seok et al., 2010), pH (Houas et al., 2001), acid concentration (Song et al., 2016), hydrothermal time (Huang et al., 2012), and concentration ratio of the synthesize solution (Karkare, 2014; Miao et al., 2015). Unfortunately, this approach involved high chemical reaction which can easily disturb and influences the preparation and synthesis steps and sometimes affects the overall synthesis time. Basically, TiO2 has three different crystalline phases which are rutile phase (tetragonal), anatase phase (tetragonal) and brookite phase RESEARCH ARTICLE