Development of a High-Performance Mediatorless Microbial Fuel Cell Comprising a Catalytic Steel Anode

Abstract

The present paper reports for the first time the construction of a sugar cane bagasse-mediated double-chambered microbial fuel cell (MFC), consisting of a novel bioanode of an iron/titanium Ni–P composite. This anode could facilitate uninterrupted extracellular electron transfer (EET) from bacteria (mixed culture). The Ni–P composite anode had a significant corrosion resistance and enhanced electrocatalytic activity. The corrosion rate was reduced to 0.187 mmpy, which was 3 times less than that of the noncomposite anode. A steady decrease in internal resistance from 3.84 × 103 Ω to 2.94 × 102 Ω was achieved with the incorporation of the iron/titanium-based composite on the anode surface. The presence of Fe (III) ion centers in the composite surface favored electroactive biofilm formation and enhanced the capacitive nature of the anode, thereby accelerating EET. The constructed MFC showed an internal resistance as low as 1.12 × 10–2 Ω in comparison with the control MFC. This led to a very high power density of ∼2.1 W/m2, which was 20% higher than that of the control MFC, while a stacked MFC obtained a maximum open-circuit potential of 3.2 V with power density and current density outputs of 6.3 W/m2 and 2.7 mA/m2, respectively. Even though an extensive amount of literature is available in this field, this report is the first of its kind because it includes such a simple reproducible system that can be extended to other similar systems.

Tuning of Surface Characteristics of Anodes for Efficient and Sustained Power Generation in Microbial Fuel Cells

“…The most prominent diffraction peaks obtained at 2θ = 44.56 for the plane (111) correspond to Ni face-centered cubic crystals and Ni 3 P body-centered tetragonal phase (JCPDS-01-1266). The presence of a sharp peak implies the existence of a microcrystalline structure of Ni–P coating. , In addition, diffraction peaks are obtained at 2θ = 38.6 and 55.3 for the planes (411) and (032), respectively, corresponding to the orthorhombic pseudobrookite Fe 2 TiO 5 composite (JCPDS41-1432), and this confirms the successful incorporation of the Fe 2 TiO 5 composite into the Ni–P coatings …”

“…In addition, the tuned content of Ti in the coatings is predicted to enhance the conductivity of the electrode. The combination of these together can increase the electron-transfer kinetics . Thus, the developed composite-coated electrode can be used as an ideal electrode for the fabrication of MFCs.…”

“…Thus, the impact of open macrostructure of the electrodes on the kinetic performance was evaluated from Nyquist responses (Figure S4B), and the electrical equivalent circuit parameters obtained after fitting the experimental data are illustrated in Table S1. All the selected electrodes exhibit single incomplete semicircle, but with considerable difference in diameter, which indicates the occurrence of the same fundamental process with difference only in their electrochemically active surface area . Hence, the variation in the electrochemically active surface area of the different electrodes is evaluated from the double-layer capacitance ( C dl ) values.…”

“…Recent research in our laboratory invariably proved that the mild steel modified with an electroless pseudobrookite Fe 2 TiO 5 composite could enhance the bacterial attachment and power generation as compared to that of the bare mild steel anode . Hence, presently, our approach is to improve the bioelectrocatalytic activity of the mild steel-based composite-coated electrode by tuning both microstructure and macrostructure via modifying the surface configuration.…”

Degradation of Diclofenac in Urine by Electro-Permanganate Process Driven by Microbial Fuel Cells

“…Moreover, the electrochemical performance at different external resistance values was also evaluated. As shown in Figure 4b, the output potential and current density all decreased with the increases in external resistance owing to the large diffusional resistance and overpotential [39,40]. Hence, the current density decreased from 0.41 to 0.07 A m −2 when the external resistance increased from 500 to 5000 Ω.…”