Catalyst In Microbial Fuel Cell Research Articles

Hydrothermal synthesis of tungsten oxide photo/electrocatalysts: precursor-driven morphological tailoring and electrochemical performance for hydrogen evolution and oxygen reduction reaction application.

A hydrothermal approach was adopted to synthesize tungsten oxide (WO3) nanocatalysts with tailored morphology, using oxalic acid (H2C2O4) and hydrochloric acid (HCl) as precursors. This precursor-driven method yielded two distinct WO3 catalysts with unique structural and functional properties, viz. rod-shaped WO3-ox and nanoflower-shaped WO3-h. Characterization by FESEM and XRD revealed variations in morphology and crystallite size, contributing to their specialized catalytic applications. UV-Vis spectroscopy confirmed strong UV absorption by WO3-ox at 283.57nm with an optical band gap of 2.86eV, making it ideal for photocatalytic activities. Electrochemical analysis demonstrated that WO3-ox effectively drives the hydrogen evolution reaction (HER), while WO3-h is more suitable for the oxygen reduction reaction (ORR), an essential process in microbial fuel cells (MFCs). In practical applications, WO3-ox achieved an 83.9% degradation efficiency of methylene blue (MB) within 3h, validating its high photocatalytic efficacy for wastewater treatment. Meanwhile, WO3-h, utilized as a cathode catalyst in MFCs, significantly enhanced system performance, elevating chemical oxygen demand (COD) removal efficiency to 78.7% and improving coulombic efficiency by 3%. These findings underscore the potential of precursor-driven hydrothermal synthesis for optimizing WO3 catalysts tailored for energy and environmental applications, specifically in hydrogen production and sustainable wastewater treatment systems.

Multi-metal ferrite as a promising catalyst for oxygen reduction reaction in microbial fuel cell.

Improving catalytic activity of cathode with noble metal-free catalysts can significantly establish microbial fuel cells (MFCs) as a sustainable and economically affordable technology. This investigation aimed to assess the viability of utilizing tri-metal ferrite (Co0.5Cu0.5 Bi0.1Fe1.9O4) as an oxygen reduction reaction (ORR) catalyst to enhance the performance of cathode in MFCs. Trimetallic ferrite was synthesized using a sol-gel auto-combustion process. Electrochemical evaluations were conducted to assess the efficacy of as-synthesized composite as an ORR catalyst, employing electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). This evaluation revealed that the impregnation of bismuth in the Co-Cu-ferrite structure improves the reduction current response and reduces the charge transfer resistance. Further experiments were conducted to test the performance of this catalyst in an MFC. The MFC with tri-metal ferrite catalyst generated a power density of 11.44 W/m3 with 21.4% coulombic efficiency (CE), which was found to be comparable with commercially available 10% Pt/C used as cathode catalyst in MFC (power density of 12.14 W/m3 and CE of 23.1%) and substantially greater than MFC having bare carbon felt cathode without any catalyst (power density of 2.49 W/m3 and CE of 7.39%). This exceptionally inexpensive ORR catalyst has adequate merit to replace commercial costlier platinum-based cathode catalysts for upscaling MFCs.

Xerogel-Derived Manganese Oxide/N-Doped Carbon as a Non-Precious Metal-Based Oxygen Reduction Reaction Catalyst in Microbial Fuel Cells for Energy Conversion Applications.

Current study provides a novel strategy to synthesize the nano-sized MnO nanoparticles from the quick, ascendable, sol-gel synthesis strategy. The MnO nanoparticles are supported on nitrogen-doped carbon derived from the cheap sustainable source. The resulting MnO/N-doped carbon catalysts developed in this study are systematically evaluated via several physicochemical and electrochemical characterizations. The physicochemical characterizations confirms that the crystalline MnO nanoparticles are successfully synthesized and are supported on N-doped carbons, ascertained from the X-ray diffraction and transmission electron microscopic studies. In addition, the developed MnO/N-doped carbon catalyst was also found to have adequate surface area and porosity, similar to the traditional Pt/C catalyst. Detailed investigations on the effect of the nitrogen precursor, heat treatment temperature, and N-doped carbon support on the ORR activity is established in 0.1 M of HClO4. It was found that the MnO/N-doped carbon catalysts showed enhanced ORR activity with a half-wave potential of 0.69 V vs. RHE, with nearly four electron transfers and excellent stability with just a loss of 10 mV after 20,000 potential cycles. When analyzed as an ORR catalyst in dual-chamber microbial fuel cells (DCMFC) with Nafion 117 membrane as the electrolyte, the MnO/N-doped carbon catalyst exhibited a volumetric power density of ~45 mW m2 and a 60% degradation of organic matter in 30 days of continuous operation.

Use of biogenic silver nanoparticles on the cathode to improve bioelectricity production in microbial fuel cells.

To date, research on microbial fuel cells (MFCs) has. focused on the production of cost-effective, high-performance electrodes and catalysts. The present study focuses on the synthesis of silver nanoparticles (AgNPs) by Pseudomonas sp. and evaluates their role as an oxygen reduction reaction (ORR) catalyst in an MFC. Biogenic AgNPs were synthesized from Pseudomonas aeruginosa via facile hydrothermal synthesis. The physiochemical characterization of the biogenic AgNPs was conducted via scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-visible spectrum analysis. SEM micrographs showed a spherical cluster of AgNPs of 20-100nm in size. The oxygen reduction reaction (ORR) ability of the biogenic AgNPs was studied using cyclic voltammetry (CV). The oxygen reduction peaks were observed at 0.43V, 0.42V, 0.410V, and 0.39V. Different concentrations of biogenic AgNPs (0.25-1.0mg/cm2) were used as ORR catalysts at the cathode in the MFC. A steady increase in the power production was observed with increasing concentrations of biogenic AgNPs. Biogenic AgNPs loaded with 1.0mg/cm2 exhibited the highest power density (PDmax) of 4.70W/m3, which was approximately 26.30% higher than the PDmax of the sample loaded with 0.25mg/cm2. The highest COD removal and Coulombic efficiency (CE) were also observed in biogenic AgNPs loaded with 1.0mg/cm2 (83.8% and 11.7%, respectively). However, the opposite trend was observed in the internal resistance of the MFC. The lowest internal resistance was observed in a 1.0mg/cm2 loading (87Ω), which is attributed to the high oxygen reduction kinetics at the surface of the cathode by the biogenic AgNPs. The results of this study conclude that biogenic AgNPs are a cost-effective, high-performance ORR catalyst in MFCs.

Metal-organic framework-derived Fe/Fe3C embedded in N-doped carbon as a highly efficient oxygen reduction catalyst for microbial fuel cells

Microbial fuel cells (MFCs) have become new energy approach for sustainable development. The exploitation of economic and efficient electrocatalysts for the oxygen reduction reaction (ORR) is essential for obtaining remarkable MFCs performance. Herein, metal–organic framework (MOF)-derived Fe/Fe3C embedded in nitrogen-doped carbon hybrids, prepared through a simple solvothermal and pyrolysis approach, are highly efficient ORR catalysts. The unique mixed dimension (1D/2D) and mesoporous structure provide abundant active sites and build transfer channels for improvement. Additionally, the presence of nitrogen doping played an important role to accelerate electron diffusion and transport. A maximum power density of 1974.75 ± 26.16 mW m−2 is earned by Fe/Fe3C/NC-800, and is 1.45 times of 20% Pt/C (1366.45 ± 28.65 mW m−2). Therefore, the Fe/Fe3C/NC catalyst is a prospective ORR catalyst in MFCs and in future renewable energy storage and conversion technologies.

Fe-N-C-based cathode catalyst enhances redox reaction performance of microbial fuel cells: Azo dyes degradation accompanied by electricity generation

Microbial fuel cell (MFC) is a promising technology for the treatment of textile industry wastewater and energy recovering. However, insufficient power for redox reaction and costly cathode catalyst limit the application of MFCs. Herein, we proposed an environmentally friendly and convenient approach for Fe-N-C-based catalysts synthesis and confirmed their satisfactory effects. The results showed that graphitized structures, pyridine-N and graphitic-N enhanced the conductivity of pomelo peel-derived carbon (PPC). In addition, the existence of Fe3C nanocrystals, Fe-Nx active sites and the rod-like carbon nanotubes (CNTs) was favorable for the synthetic catalyst. Meanwhile, the effective removal of Congo Red (CR) (99.0%) and COD (86.6%) was achieved at the precursor mass ratio was 2 under neutral conditions, accompanied by a maximum power output of 184 mW·m-2. It was clarified that electrons preferentially break the azo bond (-N = N-) of CR and the intermediates mainly included the benzene ring and the naphthalene ring. Microbial community analysis showed that Proteobacteria (56.5%), Gammaproteobacteria (44.6%) and Acinetobacter (29.5%) dominated at the phylum, class and genus levels of the anodic biofilm, respectively. In general, this study provides an innovative substitute for cathode catalyst in MFCs and the synthesized Fe-N-C-based catalyst could be widely employed in engineering owing to its admirable intrinsic activity.

Application of Low-Cost Plant-Derived Carbon Dots as a Sustainable Anode Catalyst in Microbial Fuel Cells for Improved Wastewater Treatment and Power Output

Microbial fuel cells (MFC) can generate electric energy from wastewater which can be enhanced further by anode catalysts. The recovery of electrons produced by oxidation of organics catalyzed by bacteria in the anode was enhanced when carbon dots(CDs) were added into the MFC. In this present study, a novel strategy for designing anode material and the fabrication of a high-efficient and environmentally friendly anode for energy generation from wastewater was reported. The CDs were synthesized by the pyrolysis of a peanut shell at the temperature of 250 °C for 2 h with a heating rate of 10 °C min−1. Thus synthesized CDs were characterized by transmission electron microscopy (TEM), UV/Vis spectroscopy, and fluorescence spectroscopy. The TEM analysis showed morphology with an average size of 1.62 nm. The UV/Vis absorbance of the CDs shows a wide absorption band without a characteristic peak. The excitation spectrum of CDs recorded at the emission wavelength of 440 nm exhibits a peak around 320 nm. CDs were investigated as an anode material in a MFC utilizing acetate as the organic substrate. The average chemical oxygen demand (COD) removal in closed circuit operation mode was 89%. The maximum power density production (7.2 W/m3) was observed in MFC containing 1 mg/cm2 CD-impregnated anode (CDsIA). The CDsIA provides the ability to promote efficient biofilm formation. These results emphasize the application of CD-based electrodes in MFCs for the simultaneous treatment of wastewater and electricity generation while also providing additional benefits.

Cu, Co embedded N-enriched mesoporous carbon cathode catalyst for the efficient bioelectrochemical removal of phenanthrene in microbial fuel cell

The development of high-efficiency and economical oxygen reduction reaction (ORR) electrocatalysts is vital for the improvement of renewable energy storage and conversion technology. As a promising energy conversion technology, the performance of microbial fuel cell (MFC) has aroused worldwide interest in recent years owing to its power generation capacity and potential for wastewater treatment. In an aquatic environment, phenanthrene (Phe) is one of the most abundant polycyclic aromatic hydrocarbons. We synthesized a series of CuCo samples successfully via simple in- situ growth and thermal decomposition method. In addition, a single-chamber, air-cathode MFC is investigated for the degradation of phenanthrene in neutral solution. The cathode catalyst 1.5 CuCo@NC-800 exhibits a maximum power density (MPD) of 3248.68 ± 28.21 mW m−2 in initial cycles and maintained at 95.25% after the Phe degradation. And in this study, the reactor with 1.5 CuCo@NC-800 catalyst can effectively reduce Phe at low concentrations and remain above the rate of 98%. Therefore, 1.5 CuCo@NC-800 showed great potential to become a material candidate for non-noble cathode catalyst in MFC.

A review on graphene / graphene oxide supported electrodes for microbial fuel cell applications: Challenges and prospects

Microbial Fuel Cell (MFC) has gained great interest as an alternative green technology for bioenergy generation along with reduced sludge production, nutrient recovery, removal of COD and color, etc. during wastewater treatment. However, the MFC has several challenges for real-time applications due to less power output and high ohmic resistance and fabrication (electrode and membrane) cost. Several kinds of research have been carried out to increase energy production by reducing various losses associated with electrodes in the MFC. Though, carbonaceous electrodes (carbon and graphite) are the key materials for the anode and cathode side, since these have a higher surface area, good biocompatibility, low cost, and good mechanical strength. Graphene or graphene oxide-based nanocomposite can be an ideal substitute for electrode modifications and an alternative for an expensive anode and cathode catalyst in MFC. Graphene oxide synthesis from waste material such as waste biomass, agricultural, plastic waste, etc. is added advantages of minimizing the cost of the electrodes. But, the synthesis of graphene is quite expensive and has limitations in economic feasibility for bioelectricity production in MFC. Hence, the present review deals with the anode and cathode electrode modification with graphene-based nanocomposites, synthesis of graphene/graphene oxide from various raw materials, and its application in MFC. The current challenges and future outlook on graphene-based composites on MFC performance are also discussed.

Mnco2s4 Nanoflakes Deposited on Activated Carbon as Efficient Oxygen Reduction Catalyst in Microbial Fuel Cells

Mnco2s4 Nanoflakes Deposited on Activated Carbon as Efficient Oxygen Reduction Catalyst in Microbial Fuel Cells

FeCo alloys in-situ formed in Co/Co2P/N-doped carbon as a durable catalyst for boosting bio-electrons-driven oxygen reduction in microbial fuel cells

Non-noble metal catalyst with high catalytic activity and stability towards oxygen reduction reaction (ORR) is critical for durable bioelectricity generation in air-cathode microbial fuel cells (MFCs). Herein, nitrogen-doped (iron-cobalt alloy)/cobalt/cobalt phosphide/partly-graphitized carbon ((FeCo)/Co/Co2P/NPGC) catalysts are prepared by using cornstalks via a facile method. Carbonization temperature exerts a great effect on catalyst structure and ORR activity. FeCo alloys are in-situ formed in the catalysts above 900 °C, which are considered as the highly-active component in catalyzing ORR. AC-MFC with FeCo/Co/Co2P/NPGC (950 °C) cathode shows the highest power density of 997.74 ± 5 mW m−2, which only declines 8.65% after 90 d operation. The highest Coulombic efficiency (23.3%) and the lowest charge transfer resistance (22.89 Ω) are obtained by FeCo/Co/Co2P/NPGC (950 °C) cathode, indicating that it has a high bio-electrons recycling rate. Highly porous structure (539.50 m2 g−1) can provide the interconnected channels to facilitate the transport of O2. FeCo alloys promote charge transfer and catalytic decomposition of H2O2 to •OH and •O2−, which inhibits cathodic biofilm growth to improve ORR durability. Synergies between metallic components (FeCo/Co/Co2P) and N-doped carbon energetically improve the ORR catalytic activity of (FeCo)/Co/Co2P/NPGC catalysts, which have the potential to be widely used as catalysts in MFCs.

Chemical Polymerization Method to Synthesize Polyaniline as a Novel Anode Catalyst in Microbial Fuel Cell

Chemical Polymerization Method to Synthesize Polyaniline as a Novel Anode Catalyst in Microbial Fuel Cell

High-Density Polyethylene Waste-Derived Carbon as a Low-Cost Cathode Catalyst in Microbial Fuel Cell

High-Density Polyethylene Waste-Derived Carbon as a Low-Cost Cathode Catalyst in Microbial Fuel Cell

Surface Roughness and Electrochemical Performance Properties of Biosynthesized α-MnO2/NiO-Based Polyaniline Ternary Composites as Efficient Catalysts in Microbial Fuel Cells

In this study, biosynthesized α-MnO2/NiO NPs and chemically oxidative polyaniline (PANI) were synthesized to form ternary composite anode material for MFC. The synthesized materials were characterized with different materials (UV-Vis, FTIR, XRD, TGA-DTA-DSC, SEM-EDX-Gwyddion, CV, and EIS) to deeply examine their optical, structural, morphological, thermal, roughness, and electrocatalytic properties. The degree of surface roughness for α-MnO2/NiO/PANI was23.65±5.652 nm. This value was higher than the pure α-MnO2, pure PANI, and even α-MnO2/PANI nanocomposite due to surface modification. The total charge storing performance for bare PGE, α-MnO2/PGE, PANI/PGE, α-MnO2/PANI/PGE, and α-MnO2/NiO/PANI/PGE were 5.291, 17.267, 20.659, 23.258, and 24.456 mC. From this, the charge storing performance formed by α-MnO2/NiO/PANI-modified PGE was highest, indicating that this electrode is best in cycle stability and increases its life cycle during energy conversion time in MFC. This is also supported by its effective surface area, having a value of 0.00984 cm2. From this, it is evidenced that the ternary composite catalyst-modified anode facilitates the fast electrocatalytic activity as observed from its high peak current and lower peak-to-peak potential separation (ΔEp=0.216 V) than other electrodes. Such surface modification helps to store more electrical charge by increasing electrical conductivity during its charge/discharge processing time. In addition, the lower charge transfer resistance property with a value of 788.9 Ω and the fast heterogeneous electron transfer rate of ~2.92 s-1 enable to facilitate glucose oxidation, and this enhances to produce high power output and increase wastewater treatment efficiency. As a result, the bioelectrical activity of α-MnO2/NiO/PANI composite-modified PGE was very effective in producing a maximum power density of 506.96 mW m-2 with COD of 81.92%. The above observations justified that α-MnO2/NiO/PANI/PGE serves as an effective anode material in double-chambered MFC application.

Fungal-mediated electrochemical system: Prospects, applications and challenges.

Microbial fuel cells (MFCs) that generate bioelectricity from biodegradable waste have received considerable attention from biologists. Fungi play a significant role as both anodic and cathodic catalysts in MFCs. Saccharomyces cerevisiae is a fungus with an ability to transfer electrons through mediators such as methylene blue (MB), neutral red (NR) or even without a mediator. This unique role of fungal cells in exocellular electron transfer (EET) and their interactions with electrodes hold a lot of promise in areas such as wastewater treatment where yeast cell-based MFCs can be used. The present article highlights the physico-chemical factors affecting the performance of fungal-mediated MFCs in terms of power output and degradation of organic pollutants, along with the challenges associated with fungal MFCs. In addition, to this comparative assessment of fungal-mediated bio-electrochemical systems, their development, possible applications and potential challenges are also discussed.

Proficient Sanitary Wastewater Treatment in Laboratory and Field-Scale Microbial Fuel Cell with Anti-Biofouling Cu0.5Mn0.5Fe2O4 as Cathode Catalyst

For successful field-scale application of microbial fuel cell (MFC), the power recovery from field-scale MFC needs to be improved considerably with simultaneous reduction in its fabrication cost. These problems can be addressed by applying low-cost and efficient cathode catalyst in MFCs. In this regard, Cu0.5Mn0.5Fe2O4 (CuMnFe) was synthesized and applied as cathode catalyst in lab and field-scale MFCs with capacity of 150 ml and 25 l, respectively. Lab-scale MFC having CuMnFe as cathode catalyst demonstrated power density of 176.0 ± 8.2 mW m−2, which was competitive with MFC having Pt as cathode catalyst (183.0 ± 12.6 mW m−2) and it was about seven times higher than control MFC (25.5 ± 4.5 mW m−2) having no catalyst. Application of CuMnFe as cathode catalyst in field-scale MFC produced power density of 7.74 mW m−2, which was three-times higher than the power produced by the field-scale MFC operated without any cathode catalyst (2.58 mW m−2). The cathode catalyst CuMnFe also demonstrated excellent anti-biofouling properties, which in turn improved the power production of field-scale MFC. Therefore, low-cost CuMnFe can be anticipated as an efficacious cathode catalyst for application in MFCs that would produce long term stable higher power, while offering simultaneous treatment to wastewater.

Preparation and Application of Fe-N Co-Doped GNR@CNT Cathode Oxygen Reduction Reaction Catalyst in Microbial Fuel Cells.

Through one-step pyrolysis, non-noble-metal oxygen reduction reaction (ORR) electrocatalysts were constructed from ferric trichloride, melamine, and graphene nanoribbon@carbon nanotube (GNR@CNT), in which a portion of the multiwall carbon nanotube is unwrapped/unzipped radially, and thus graphene nanoribbon is exposed. In this study, Fe-N/GNR@CNT materials were used as an air-cathode electrocatalyst in microbial fuel cells (MFCs) for the first time. The Fe-N/C shows similar power generation ability to commercial Pt/C, and its electron transfer number is 3.57, indicating that the ORR process primarily occurs with 4-electron. Fe species, pyridinic-N, graphitic-N, and oxygen-containing groups existing in GNR@CNT frameworks are likely to endow the electrocatalysts with good ORR performance, suggesting that a GNR@CNT-based carbon supporter would be a good candidate for the non-precious metal catalyst to replace Pt-based precious metal.

Laccase Immobilization Strategies for Application as a Cathode Catalyst in Microbial Fuel Cells for Azo Dye Decolourization.

Enzymatic biocathodes have the potential to replace platinum as an expensive catalyst for the oxygen reduction reaction in microbial fuel cells (MFCs). However, enzymes are fragile and prone to loss of activity with time. This could be circumvented by using suitable immobilization techniques to maintain the activity and increase longevity of the enzyme. In the present study, laccase from Trametes versicolor was immobilized using three different approaches, i.e., crosslinking with electropolymerized polyaniline (PANI), entrapment in copper alginate beads (Cu-Alg), and encapsulation in Nafion micelles (Nafion), in the absence of redox mediators. These laccase systems were employed in cathode chambers of MFCs for decolourization of Acid orange 7 (AO7) dye. The biocatalyst in the anode chamber was Shewanella oneidensis MR-1 in each case. The enzyme in the immobilized states was compared with freely suspended enzyme with respect to dye decolourization at the cathode, enzyme activity retention, power production, and reusability. PANI laccase showed the highest stability and activity, producing a power density of 38 ± 1.7 mW m−2 compared to 25.6 ± 2.1 mW m−2 for Nafion laccase, 14.7 ± 1.04 mW m−2 for Cu-Alg laccase, and 28 ± 0.98 mW m−2 for the freely suspended enzyme. There was 81% enzyme activity retained after 1 cycle (5 days) for PANI laccase compared to 69% for Nafion and 61.5% activity for Cu-alginate laccase and 23.8% activity retention for the freely suspended laccase compared to initial activity. The dye decolourization was highest for freely suspended enzyme with over 85% decolourization whereas for PANI it was 75.6%, Nafion 73%, and 81% Cu-alginate systems, respectively. All the immobilized laccase systems were reusable for two more cycles. The current study explores the potential of laccase immobilized biocathode for dye decolourization in a microbial fuel cell.

Activated Carbon Derived from Rice Husk as Efficient Oxygen Reduction Catalyst in Microbial Fuel Cell

AbstractIn microbial fuel cells (MFCs), an important factor limiting practical applications is the high catalyst cost in cathode. Herein a rice husk‐based porous carbon made through hydrolysis, activation and rolling was used as novel cathode. These porous carbons were characterized by SEM, XPS and BET analysis, and electrochemical measurements including linear sweep voltammetry and Tafel test were investigated. A maximum powder density (317.7±0.4 mW m−2) on AC‐KOH‐1h with the largest BET surface area of 1809 m2 g−1 was obtained. This study revealed a fresh territory about the application of porous carbon produced by renewable resources for MFC electrode.

Performance evaluation of poly(aniline-co-pyrrole) wrapped titanium dioxide nanocomposite as an air-cathode catalyst material for microbial fuel cell.

A simple, inexpensive in situ oxidative polymerization of aniline and pyrrole using ammonium persulfate (APS) as oxidant and hydrochloric acid (HCl) as dopant has been used to synthesize a hybrid (PAni-Co-PPy)@TiO2 nanocomposite with titanium oxide (TiO2) nanoparticles (NPs) wrapped into (PAni-Co-PPy) copolymer. The synthesized nanocomposite has been shown with higher oxygen reduction reactions (ORR) as an excellent cathode material for higher performance in the complex of (PAni-Co-PPy)+/TiO2(O-). The charge transport phenomenon between TiO2 and (PAni-Co-PPy)+ were found adequate with subsequent delocalization of electron/s at PAni and PPy. The self-doping nature of TiO2 (O-) played a vital role in oxygen adsorption and desorption process. With higher electrical conductivity and surface area, these were tested in microbial fuel cells (MFCs) for ORRs at cathode. This yielded a relatively higher current and power density output as compared to PAni@TiO2, PPy@TiO2, and commercially available Pt/C cathode catalysts in MFC system. In overall, the prepared (PAni-Co-PPy)@TiO2 nano-hybrid cathode delivered ~2.03 fold higher power density as compared to Pt/C catalyst, i.e. ~987.36±49mW/m2 against ~481.02±24mW/m2. The properties of electro-catalysts established an improved synergetic effect between TiO2 NPs and (PAni-Co-PPy). In effect, the enhanced surface area and electrochemical properties of the prepared (PAni-Co-PPy)@TiO2 nano-hybrid system is depicted here as an effective cathode catalyst in MFCs for improved performance.