Graphene Based Materials for Arsenic Sensing and Removal from Contaminated Water

Abstract

Environmental pollution especially toxic gases, heavy metal ions and organic pollutants in air and water, caused by industry and agricultural activities, severely threaten ecological balance and human health, and have received extensive attention worldwide. Arsenic contamination of groundwater is a critical problem that affects millions of people across the world and results in severe diseases such as skin or lung cancer and bladder cancer. Widespread arsenic contamination of groundwater has led to a massive epidemic of arsenic poisoning in Asia and America, especially such as India, Bangladesh, Vietnam, Cambodia, Thailand, southwest USA, Canada, Chile, and neighboring countries. Graphene has become a promising material for many different applications, such as nanoelectronic devices, physical, chemical and biochemical sensors, transparent conductive films, clean energy devices, or nanocomposite formulation. Sensing applications using graphene sheets as transducers have experienced a surge in the last few years, especially for gas sensing platforms, or electrochemical sensors, because of the high electrical conductivity of graphene. In this work, we investigate the synthesis of graphene by methane decomposition at 1000 °C onto free standing electrodeposited substrates, studying the effects of the electrochemical synthesis onto graphene quality. The growth of good quality graphene layers is also discussed in terms of the role played by grain boundaries and diffusion at the grain boundaries. As an advance of graphene studies, 2D graphene nanomaterials have been applied to arsenic sensing and removal from contaminated water. The work will discuss our latest studies and progresses on the application of graphene-based materials in the environmental protection and detection for arsenic contaminated waters. The work will present the use of graphene based electrodes for electrochemical sensing of arsenic; a similar approach will be discuss for arsenic removal, discussing kinetics and performances of the process.