Understanding the Corrosion Behaviour of Graphite in Peat Environment for Environmental and Sustainability Applications

Abstract

Graphite, which is one of the most remarkable carbon materials for industrial applications, is a heat exchanger component material in the phosphoric acid industry, bipolar layer or electrode material in vanadium redox flow batteries, electrode material for advanced oxidation processes, electrode material for lead-acid batteries, electrode material in fuel cells and microbial fuel cells, and more interesting, as moderator or core material in nuclear reactors used. Corrosion, one of the most important problems of graphite materials widely used in such important areas of the industry, has not been adequately addressed, although it is an issue ofprimary importance for the long-term stability of carbon materials. Moreover, since corrosion studies of graphite have mostly focused on its performance in artificial environments, studies on how they would perform in real world situations are quite poor. Based on these deficiencies, in this study, graphite corrosion was investigated in aqueous peat environment, which is a natural material, anaerobic, contains bacteria and provides a complex environment, in order to represent real world conditions. Experiments performed to determine corrosion behaviour show that graphite material is prone to corrosion in the peat environment and pitting corrosion is especially dominant. However, graphite exhibited good corrosion resistance in the peat environment and its corrosion rate was around 1.117x10-7 mm/year. This is in the very low corrosion category (<= 0.025 mm/year) according to the corrosion rate classification of equipment in the chemical industry. Therefore, graphite is promising as a more sustainable, corrosion-resistant electrode material for fuel cells, microbial fuel cells, biosensors.