Stainless steel coated with carbon nanofiber/PDMS composite as anodes in microbial fuel cells

Abstract

Modification of electrode surfaces is a promising strategy to improve microbial fuel cell (MFC) performance. Here we report a new functionalization process to improve interfacial electron transfer, biocompatibility and corrosion resistance of stainless steel (SS) electrodes used as anodes in MFCs. SS anodes prepared by surface modification with a thin layer (200 μm) of conducting composite made of polydimethylsiloxane (PDMS) doped with commercially available carbon nanofibers (CNF), are described. Electrochemical characterization showed that the corrosion rate of SS electrode in an acid solution decreased from 367 μm.y −1 to 31 μm.y −1 after CNF-PDMS coating. Electric characterization demonstrated that the maximum power density generated by MFCs after 16 days with SS/CNF-PDMS anodes (19 mW.m −2 ) is 5 times higher and more stable than that with unmodified SS (3.7 mW.m −2 ). The cyclic voltammetry analysis indicated that the electrochemical activity of the modified anode was enhanced significantly after 16 days and the electron transfer was facilitated by CNF-PDMS modification. Microscopic observations and electrochemical characterization showed that CNF-PDMS composite improved biocompatibility and corrosion resistance of the SS anode surfaces. These results confirmed that the CNF-PDMS modification is a promising approach to improve the properties of anode materials for MFC application.

Carbon Nano-Fiber/PDMS Composite Used as Corrosion-Resistant Coating for Copper Anodes in Microbial Fuel Cells

“…Indeed, the authors justified this poor electrical performance by the low conductivity of the polyaniline and the compact passivated layer (oxide layer) formed between the polymer-Cu surfaces. Compared with the performance of MFCs with other anode materials using wastewater as inoculum, the power density of 500 µm-thick CNF-PDMS coated Cu anodes was higher than what we previously reported for stainless steel anodes coated with CNF-PDMS (19 mW m −2 ) [19] and bare carbon clothe (50 mW m −2 ) [1]. However, the power density was lower than those obtained with carbon felt (100 mW m −2 ) [29] and carbon paper (104 mW m −2 ) [28] anodes, as previously described.…”

“…In this study, Cu anode surfaces were modified with thin layer of low-cost and mechanical stable CNF-PDMS (Polydimethylsiloxane) coating (Figure 1). PDMS is an attractive polymer with physically and chemically stable properties [19]. Recently, we demonstrated that PDMS doped with CNF is a conducting polymer providing more significant electrical active sites for electron transfer between exoelectrogenic bacteria and stainless steel coated electrodes [19].…”

“…PDMS is an attractive polymer with physically and chemically stable properties [19]. Recently, we demonstrated that PDMS doped with CNF is a conducting polymer providing more significant electrical active sites for electron transfer between exoelectrogenic bacteria and stainless steel coated electrodes [19]. This coating method could be deposited on large electrode surfaces at low costs.…”

A Novel Energy-from-Waste Approach for Electrical Energy Production by Galvano–Fenton Process

“…Both configurations offer better degradation performances than classical Fenton and conventional ZVI-based Fenton. Moreover, electrical energy performances of the GF process obtained with both the GF-A and GF-B configuration are higher than electrical performances of microbial fuel cell technology, another electrochemical technology using bacteria to produce electrical energy from biodegradable organic molecules in wastewater with maximum power comprised between 1 mW·m −2 and 1 W·m −2 [ 33 , 34 ]. The electrical energy generated by the GF process can be harvested and exploited using an external circuit based on electronic power converters and digital processing devices that extract the maximum amount of electrical power and increase the voltage as needed.…”

Carbon‐Based Composites as Anodes for Microbial Fuel Cells: Recent Advances and Challenges

“…Coating a layer of polymers on carbon matrix can improve the bacteria-electrode interaction, electrical conductivity, corrosion resistance and hydrophilicity, leading to a strong adhesion of microbes, extracellular electron transfer and operation stability. [247][248][249] For example, when poly(3-aminophenylboronic acid) (p-PAPBA) was coated on carbon cloth (CC) anode, the electron transport was promoted due to the chemical interaction between the cell surface and p-PAPBA film. [248] Similarly, owing to the positive charge and hydrophilicity of the ionic liquid polymer and polydiallyldimethylammonium chloride (PDDA), the electrostatic interaction with CC or carbon felt (CF) benefited the electron transfer.…”