Study the effect of calcination temperature and time on TiO 2 band gap synthesized from TiCl 4 coagulation sludge Fathin Azwina a , Mohammad Rezaei Ardani a , Siti Fatihah Ramli b , Sheikh Abdul Rezan a,⇑ , Hamidi Abdul Aziz b a School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, 14300, Malaysia b School of Civil Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, 14300, Malaysia article info Article history: Received 16 December 2019 Received in revised form 27 January 2020 Accepted 4 February 2020 Available online xxxx Keywords: Coagulation Titanium Tetrachloride (TiCl 4 ) Titanium Dioxide (TiO 2 ) Photocatalytic activity Scanning Electron Microscope abstract This study investigated the preparation of TiO 2 from generated sludge through TiCl 4 coagulation of Along Pongsu Landfill leachate. TiCl 4 with chitosan as coagulant aid were used to carry out coagulation process on the leachate. The produced sludge after coagulation process was calcined to prepare TiO 2 for photo- catalytic applications. The studied factors were including calcination temperature (400, 600 and 800 °C), calcination time (6, 9 and 12 h) and TiCl 4 dosage (800, 1000 and 1200 mg/L). The results indi- cated that the band gap of the prepared TiO 2 was changed between 3.35 eV and 2.75 eV. The morphology and phase analysis of prepared TiO 2 after calcination were investigated using Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). The XRD spectrums showed an anatase phase at lower calcination temperature and rutile phase at elevated temperature. This study confirmed that TiO 2 powder was successfully prepared from generated sludge from TiCl 4 coagulation, with the potential for photo- catalysis applications. Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the Innovative Advance- ment in Engineering & Technology. 1. Introduction The rapid growth in urban population in recent years, has been conversely affected the amount of waste production each year. Unfortunately, the most utilized method of waste management in many countries is disposal as a landfill considering the capacity and economic factors. The main problem of the landfills is the gen- eration and migration of leachates over time, which result in envi- ronment pollution due to the presence of organic or inorganic component, such as various types of bacteria and viruses as well as gas emission of the leachate [1–4]. Most common method for wastewater treatment is the coagu- lation and flocculation of wastewater using ferric chloride (FeCl 3 ) and Aluminum sulfate (Al 2 (SO 4 ) 3 ). However, the main problem of using these conventional materials is the high amount of produced sludge after treatment, which requires post treatment processes [5–7]. Moreover, the application of Al 2 (SO 4 ) 3 may result in increas- ing the Al amount in the water, which is detrimental for human health and the environment [8,9]. In order to overcome the men- tioned challenges, several studies [10,11] have investigated the potential use of Ti-salt coagulants such as TiCl 4 for wastewater treatment. The results indicated that the application of TiCl 4 was successful and cost effective considering production of less quan- tity of sludge. Moreover, the settled sludge could be used to pro- duce useful by-product of titanium dioxide (TiO 2 ) through calcination process. TiO 2 is useful material for numerous applica- tions such as solar cells or photocatalysis, considering its photocat- alytic and optical properties, chemical stability, non-toxicity, environmental friendly and human body and biocompatibility [10–16]. The main purpose of this study is to investigate the effect of change in calcination time and temperature along with different amount of TiCl 4 on the band gap of prepared TiO 2 . Furthermore, morphology and phase formation of produced TiO 2 powder from sludge after calcination process has studied. https://doi.org/10.1016/j.matpr.2020.02.088 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the Innovative Advancement in Engineering & Technology. ⇑ Corresponding author. E-mail address: srsheikh@usm.my (S. Abdul Rezan). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: F. Azwina, M. Rezaei Ardani, S. F. Ramli et al., Study the effect of calcination temperature and time on TiO 2 band gap synthesized from TiCl 4 coagulation sludge, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.02.088