Revealing the synergetic electrocatalyst behaviour of Kish graphite recovered from polyethylene plastics R. Kandeeban a , R. Brindha b , K. Manojkumar a , Khalid Mujasam Batoo c , Emad H. Raslan d , Muhammad Hadi d , Ahamad Imran c , K. Saminathan a,⇑ a Department of Chemistry, Kongunadu Arts and Science College, Coimbatore 641029, India b Center for Nanoscience and Technology, Pondicherry University, Puducherry 605014, India c King Abdullah Institute for Nanotechnology, King Saud University, P.O. Box 2455, Riyadh 1145, Saudi Arabia d Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 1145, Saudi Arabia article info Article history: Received 29 January 2021 Received in revised form 15 March 2021 Accepted 18 March 2021 Available online 23 March 2021 Keywords: Plastic recycling Kish graphite Anticorrosive Polyethylene Air battery abstract Polyethylene plastic is a threat to the environment because of its enormous usage and limited recycling options. Herewith, the study reports the synthesis of Kish graphite from polyethylene waste. These wastes was mixed with molten iron and cooled into a rod-shaped mold. The molded iron ingots contain precipitated carbon material in 2D graphitic nature, which was obtained as Kish graphite after several acid treatments. The tafel studies show the anticorrosive nature of the sample with the corrosion potential of À1.6 V. Kish graphite and manganese oxide in the ratio 40:9 exhibited higher catalytic activity towards oxygen reduction reaction. Discharge studies of Mg-air battery with graphite (80%) air cathode recorded the highest capacity of 1226.51 mAh g À1 , discharge life of 73.6 h and enhanced performance characteristics. Thus, waste polyethylene was effectively used as an supportive electrocatalyst in the Mg-air battery system. Ó 2021 Elsevier B.V. All rights reserved. 1. Introduction In recent years, the utilization of plastic has increased drastically due to multiple factors like low cost, flexibility, light- weight, and compatible moulding [1]. Polyethylene, one of the widely used polyolefin got accumulated over the years in tons. These polyethylene are hostile in nature and create massive dam- age to the ecosystem and pose a major threat to the environment [2]. Many researchers are focusing on carbonaceous materials obtained from waste plastics and cigarette filter [3–5]. Al-Enizi AM et al and co-workers have converted waste plastic bottles to metal-organic frameworks, using an indigenous chemical approach [6]. V.G. Pol et al and group synthesized energy-storing carbon material from waste plastic bags [7]. Also, the surging demand for low cost air-battery systems has increased significantly due to the depletion of fossil fuel. Especially, Mg-air batteries are expansively used due to their high theoretical energy density (3.9 KW h kg À1 ) and voltage (3.07 V) [8]. Moreover, carbon and graphitic nanostructures play significant roles as cathode, anode, catalyst, and additives in air-battery sys- tems [9]. Incidentally, improved capacity, reversibility, and ther- mal safety of Kish graphite, against the commercial graphite make it an eminent alternative for the conventional battery electrodes [10]. Different methods have been employed for the production of Kish graphite. Herein, we have utilized a cost- effective, non-toxic, and simple procedure in the preparation of graphite from polyethylene wastes. The prepared Kish graphitic nanostructures are used as an active cathode material for the fab- ricated Mg-air battery system. 2. Materials and methods All the required chemicals were bought from Merck, Germany, and used without further alterations. Initially, waste polyethylene plastics were collected from the regions of GN Mills, Coimbatore, and drilled into small pieces at a local steel manufacturing unit. Secondly, the iron pieces in bulk were melted separately at 1700°À1800 °C using a high-temperature furnace. Then, the drilled plastics were taken in a crucible, and melted Fe was poured upon it forming a solution labeled as Fe-PET. Meanwhile, to prevent the molten iron from burning the polyethylene plastics, carbon dioxide https://doi.org/10.1016/j.matlet.2021.129740 0167-577X/Ó 2021 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail address: ksaminath@gmail.com (K. Saminathan). Materials Letters 294 (2021) 129740 Contents lists available at ScienceDirect Materials Letters journal homepage: www.elsevier.com/locate/mlblue