Development of Gold Electrodes for Microbial Fuel Cells

Abstract

The microbial fuel cell (MFC) has been an important subject of study in the last decades because of its technological significance that one can produce hydrogen or electricity by wastewater treatment (bio-remediation). One of the main issues for the application of these devices on large scale is the processes and materials for the electrode fabrication. The cathode for MFC requires a catalyst to perform the reduction reaction and this work presents a simple technique to obtain thin layers of gold (TLG) supported on glass. This technique was employed to obtain TLG with different thicknesses from 848 nm to the thinnest of 137 nm. Since the gold of the TLGs presented adherence issues, a successful thermal treatment with different temperatures from 150-300 ºC was developed to avoid the gold detachment. The TLGs were tested as cathodes in a MFC and a maximum Voc of 431 mV and an Isc of 10 × 10−2 mA were obtained. The process to obtain TLGs presented here has probed to be a good option for this application since the thickness obtained and the accessible material (glass) employed as support offers a solution to the costs and the scaling issues.