In an article available as a pre-proof in the journal Carbon, researchers used electrospinning methodologies to develop an air cathode built of self-sustaining nitrogen-doped reduced graphene oxide@carbon nanofiber (N rGO@CNF) hybrid sheets suitable for microbial fuel cells.
Microbial Fuel Cells for Bioenergy Production
It is critical to develop eco-friendly and sustainable technology in light of rising climate change consequences and global energy demand.
Microbial fuel cells (MFCs), a developing biological electrolytic system with good prospects as a maintainable bioenergy generation system, have piqued scientists’ curiosity for the past few years since they can concurrently produce electricity as well as treat water waste by transforming chemical energy contained in organic material to electricity with the help of microbes and fuel (usually wastewater).
MFC outperforms alternative methods for producing energy from biological material in terms of operating and functional characteristics, such as excellent direct effectiveness, ambient temperature functioning, and no need for supplementary energy or gas treatment.
Composition of a Typical MFC
The organic materials undergo oxidation in the anode compartment, generating protons and electrons. The electrons then move via an exterior circuit, yielding electrical energy, whereas the protons move to the cathode compartment via the electrolyte, in which they interact with the electron acceptors (O2). This results in the oxygen reduction reaction (ORR), which produces water using a two-electron or four-electron mechanism.
How to Improve Performance of Air Cathode in MFCs
In a singular chambered microbial fuel cell, the typical air cathode comprises of three parts: the catalytic layer (CL), the substrate or the supporting layer (SL), and the conducting gas diffusion layer (GDL). Since the effectiveness of the air cathode is mostly determined by the catalytic layer, substantial research into catalyst designing and development has been carried out to enhance ORR taking place in the air cathode.
Thanks to their high catalysis performance, composites based on platinum (Pt) are currently the most widely utilized catalytic materials, but their industrial applications have been restricted by their significant prices, limited availability, and vulnerability to deactivation induced by biofouling and poisons in MFC settings.
Carbonaceous materials have come to the fore as excellent air cathode catalytic materials for microbial fuel cells as compared to platinum and other metallic catalysts, owing to their inexpensive prices, great stability, toxin tolerance, and excellent catalysis performance in ORR, making them viable substitutes to Pt-based catalysts.
Influence of Heteroatom Doping
One of the most successful ways for improving the ORR performance of carbonaceous materials has been established to be heteroatom doping. Injecting nitrogen (N) into the carbon framework activates electrons by creating charge spots, resulting in increased ORR catalysis performance.
Owing to the ease of agglomeration of carbon-based nanomaterials, which can obstruct catalytically active spots, the ORR effectiveness of carbonaceous composites doped with heteroatoms is still not optimal. Reduced graphene oxide (rGO) is presently utilized as an alternative form of carbon-based material to produce carbon-carbon hybrids for ORR usage. The blend of rGO and N-injected nanocarbons has a higher conductance, meaning more active spots for ORR are available.
Key Findings of the Study
In this paper, self-sustaining N-injected rGO@CNF hybridized membranes were effectively constructed using an electrospinning approach involving the addition of graphene oxide to a polyacrylonitrile (PAN) mixture followed by thermal processing in an NH3 setting.
The constructed rGO@CNFs can be used as embedded cathodes in microbial fuel cells directly. Their architectures, make-up, and texture were studied, as well as their electrolytic characteristics and MFC effectiveness, which were examined against pure NCNF and CAC electrodes.
The test results showed that rGO@CNFs outperformed the pure NCNF and CAC in terms of MFC effectiveness and ORR activation. In addition, the quantity of rGO incorporated in CNF had a significant impact on ORR activity and MFC effectiveness. On the basis of these findings, electrospun self-sustaining rGO@CNF hybridized membranes are suggested to be viable direct cathode options in MFCs.
Reference
Xu, M., Wu, L., Zhu, M., Wang, Z., Huang, Z.-H., & Wang, M.-X. (2022). Self-supporting nitrogen-doped reduced graphene Oxide@Carbon nanofiber hybrid membranes as high-performance integrated air cathodes in Microbial fuel cells. Carbon. Available at: https://www.sciencedirect.com/science/article/pii/S0008622322001968?via%3Dihub

News
Does Space-Time Really Exist?
Is time something that flows — or just an illusion? Exploring space-time as either a fixed “block universe” or a dynamic fabric reveals deeper mysteries about existence, change, and the very nature of reality. [...]
Unlocking hidden soil microbes for new antibiotics
Most bacteria cannot be cultured in the lab-and that's been bad news for medicine. Many of our frontline antibiotics originated from microbes, yet as antibiotic resistance spreads and drug pipelines run dry, the soil [...]
By working together, cells can extend their senses beyond their direct environment
The story of the princess and the pea evokes an image of a highly sensitive young royal woman so refined, she can sense a pea under a stack of mattresses. When it comes to [...]
Overworked Brain Cells May Hold the Key to Parkinson’s
Scientists at Gladstone Institutes uncovered a surprising reason why dopamine-producing neurons, crucial for smooth body movements, die in Parkinson’s disease. In mice, when these neurons were kept overactive for weeks, they began to falter, [...]
Old tires find new life: Rubber particles strengthen superhydrophobic coatings against corrosion
Development of highly robust superhydrophobic anti-corrosion coating using recycled tire rubber particles. Superhydrophobic materials offer a strategy for developing marine anti-corrosion materials due to their low solid-liquid contact area and low surface energy. However, [...]
This implant could soon allow you to read minds
Mind reading: Long a science fiction fantasy, today an increasingly concrete scientific goal. Researchers at Stanford University have succeeded in decoding internal language in real time thanks to a brain implant and artificial intelligence. [...]
A New Weapon Against Cancer: Cold Plasma Destroys Hidden Tumor Cells
Cold plasma penetrates deep into tumors and attacks cancer cells. Short-lived molecules were identified as key drivers. Scientists at the Leibniz Institute for Plasma Science and Technology (INP), working with colleagues from Greifswald University Hospital and [...]
This Common Sleep Aid May Also Protect Your Brain From Alzheimer’s
Lemborexant and similar sleep medications show potential for treating tau-related disorders, including Alzheimer’s disease. New research from Washington University School of Medicine in St. Louis shows that a commonly used sleep medication can restore normal sleep patterns and [...]
Sugar-Coated Nanoparticles Boost Cancer Drug Efficacy
A team of researchers at the University of Mississippi has discovered that coating cancer treatment carrying nanoparticles in a sugar-like material increases their treatment efficacy. They reported their findings in Advanced Healthcare Materials. Over a tenth of breast [...]
Nanoparticle-Based Vaccine Shows Promise in Fighting Cancer
In a study published in OncoImmunology, researchers from the German Cancer Research Center and Heidelberg University have created a therapeutic vaccine that mobilizes the immune system to target cancer cells. The researchers demonstrated that virus peptides combined [...]
Quantitative imaging method reveals how cells rapidly sort and transport lipids
Lipids are difficult to detect with light microscopy. Using a new chemical labeling strategy, a Dresden-based team led by André Nadler at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and [...]
Ancient DNA reveals cause of world’s first recorded pandemic
Scientists have confirmed that the Justinian Plague, the world’s first recorded pandemic, was caused by Yersinia pestis, the same bacterium behind the Black Death. Dating back some 1,500 years and long described in historical texts but [...]
“AI Is Not Intelligent at All” – Expert Warns of Worldwide Threat to Human Dignity
Opaque AI systems risk undermining human rights and dignity. Global cooperation is needed to ensure protection. The rise of artificial intelligence (AI) has changed how people interact, but it also poses a global risk to human [...]
Nanomotors: Where Are They Now?
First introduced in 2004, nanomotors have steadily advanced from a scientific curiosity to a practical technology with wide-ranging applications. This article explores the key developments, recent innovations, and major uses of nanomotors today. A [...]
Study Finds 95% of Tested Beers Contain Toxic “Forever Chemicals”
Researchers found PFAS in 95% of tested beers, with the highest levels linked to contaminated local water sources. Per- and polyfluoroalkyl substances (PFAS), better known as forever chemicals, are gaining notoriety for their ability [...]
Long COVID Symptoms Are Closer To A Stroke Or Parkinson’s Disease Than Fatigue
When most people get sick with COVID-19 today, they think of it as a brief illness, similar to a cold. However, for a large number of people, the illness doesn't end there. The World [...]