Kraton based polymeric nanocomposite bioanode for the application in a biofuel cell

Laccase-loaded CaCO3 sustained-release microspheres modified SBES anode for enhance performance in the remediation of soil contaminated with phenanthrene and pyrene

This study aimed to enhance the efficiency of SBES in remediating polycyclic aromatic hydrocarbon (PAH)-contaminated soils by modifying the anode with laccase. The experiment involved four SBES anodes: a carbon nanotube-modified anode (CNT), a free laccase-modified anode (Lac), a gelatin-encapsulated laccase-modified anode (Lac-Gel), and a CaCO3 sustained-release microsphere-loaded laccase-modified (CaCO3-SMs@Laccase) anode (Lac-SMs). The CaCO3-SMs@Laccase notably extended the active period of laccase, with laccase activity in the Lac-SMs measured at 1.646 U/g after 16 days, which was significantly higher than the 0.813 U/g observed in the Lac-Gel group and the 0.206 U/g in the Lac group. The superior electricity generation and degradation efficiency observed in the Lac-SMs group were due to the sustained enzymatic activity provided by the CaCO3-SMs@Laccase. The prevention of anode acidification through CaCO3 decomposition, and promote the forward progress of electrochemical reactions. The phenanthrene (Phe) and pyrene (Pyr) removal efficiency in the soil of the Lac-SMs reached 90.78 % and 84.72 %, surpassing those of the Lac-Gel (80.36 % and 79.14 %), Lac (79.38 % and 69.31 %), and CNT (63.22 % and 56.98 %). The degradation pathway from Pyr to Phe was possible started with hydroxylation. In addition, the laccase also transformed the predominant microbial communities and metabolism pathways.

ZnS Quantum Dots Decorated on One-Dimensional Scaffold of MWCNT/PANI Conducting Nanocomposite as an Anode for Enzymatic Biofuel Cell

This study aims to design a new nanocomposite as a supporting material for wiring the enzyme to develop a bioanode in the enzymatic biofuel cell (EBFC). In this work, polyaniline-based nanocomposite was synthesized by in situ polymerization of aniline monomer. The zeta potential study of the nanofillers was carried out, which reveals the interaction between the nanofillers. The synthesized nanocomposite (MWCNT/ZnS/AgNWs/PANI) was characterized by analytical techniques, such as Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy (XRD). Furthermore, the surface morphology and the in-depth information of the synthesized nanocomposite were displayed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. In addition, the as-synthesized nanocomposite and the designed bioanode underwent the electrochemical assessment using different electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for evaluating the electrochemical behavior of the fabricated anodes. The electrochemically regulated bioanode (MWCNT/ZnS/AgNWs/PANI/Frt/GOx) obtained an open-circuit voltage of 0.55 V and produced a maximal current density of 7.6 mA cm⁻² at a glucose concentration of 50 mM prepared in phosphate buffer solution (PBS) (pH 7.0) as a supporting electrolyte at a scan rate of 100 mV s⁻¹.

A high performance nanocomposite based bioanode for biofuel cell and biosensor application

Herein, to improve the current density and sensitivity for biofuel cell and glucose sensing application, a bioanode based on redox polymer (PEI-Fc) binding polydopamine (PDA) coated MWCNTs (PEI-Fc/PDA/MWCNTs) nanocomposite and glucose oxidase (GOD) was fabricated. PDA/MWCNTs nanocomposite was prepared by spontaneous self-polymerization of dopamine on MWCNTs surface and the PEI-Fc/PDA/MWCNTs nanocomposite was prepared by a simple self-assembly method. The PEI-Fc/PDA/MWCNTs nanocomposite and the resulting bioanode were fully characterized. A maximum current density of 0.73 mA cm^-2 at the resulting bioanode was obtained by linear sweep voltammetry (LSV) at the scan rate of 50 mV s^-1 with 20 mM glucose concentration. Moreover, a linear range up to 4 mM, a high sensitivity of 57.2 μA mM^-1 cm^-2, a fast response time reaching 95% of the steady current (2 s) and a low limit of detection (0.024 mM) were achieved. The amperometric method demonstrated both the sensitivity and the stability of the bioanode for glucose-sensing was improved by the employed PDA layer. Finally, the biosensor was used for glucose detection in human serum samples showing good recoveries. This study proposed an excellent functional material prepared by a facile self-assembled method for applying in biofuel cells and second-generation biosensors.

Constructing high-performance H3PW12O40/CoS2 counter electrodes for quantum dot sensitized solar cells by reducing the surface work function of CoS2

A low cost H₃PW₁₂O₄₀ (PW₁₂)/CoS₂ complex is prepared and used as a counter electrode (CE) to combine with sandwich quantum dot sensitized solar cells (QDSSCs) composed of a TiO₂/CdS/CdSe/ZnS photoanode and polysulfide electrolyte to study their photovoltaic properties via a simple hydrothermal method. Under standard simulated sunlight, the photoelectric conversion efficiency (PCE) of 2%PW₁₂ (PW₁₂-2/CoS₂) doped CEs was 6.29%, which was significantly 67.7% higher than those of QDSSCs based on undoped CoS₂ CEs (3.75%). Due to the introduction of PW₁₂, the nanoparticles forming the hollow structure of CoS₂ changed from regular octahedra to rough nanoparticles, which increase the active sites. At the same time, the work function of CoS₂ decorated with PW₁₂ is decreased. This study and discovery demonstrate that POMs can be used to optimize CE materials and improve the photoelectric conversion efficiency of QDSSCs, which provide an experimental and theoretical basis for subsequent investigations.

Mini-Review: Recent Technologies of Electrode and System in the Enzymatic Biofuel Cell (EBFC)

Enzymatic biofuel cells (EBFCs) is one of the branches of fuel cells that can provide high potential for various applications. However, EBFC has challenges in improving the performance power output. Exploring electrode materials is one way to increase enzyme utilization and lead to a high conversion rate so that efficient enzyme loading on the electrode surface can function correctly. This paper briefly presents recent technologies developed to improve bio-catalytic properties, biocompatibility, biodegradability, implantability, and mechanical flexibility in EBFCs. Among the combinations of materials that can be studied and are interesting because of their properties, there are various nanoparticles, carbon-based materials, and conductive polymers; all three have the advantages of chemical stability and enhanced electron transfer. The methods to immobilize enzymes, and support and substrate issues are also covered in this paper. In addition, the EBFC system is also explored and developed as suitable for applications such as self-pumping and microfluidic EBFC.

Simulation of the Electrochemical Impedance in a Three-Dimensional, Complex Microstructure of Solid Oxide Fuel Cell Cathode and Its Application in the Microstructure Characterization

Electrochemical impedance spectroscopy (EIS) is a powerful technique for material characterization and diagnosis of the solid oxide fuel cells (SOFC) as it enables separation of different phenomena such as bulk diffusion and surface reaction that occur simultaneously in the SOFC. In this work, we simulate the electrochemical impedance in an experimentally determined, three-dimensional (3D) microstructure of a mixed ion-electron conducting (MIEC) SOFC cathode. We determine the impedance response by solving the mass conservation equation in the cathode under the conditions of an AC load across the cathode’s thickness and surface reaction at the pore/solid interface. Our simulation results reveal a need for modifying the Adler-Lane-Steele model, which is widely used for fitting the impedance behavior of a MIEC cathode, to account for the difference in the oscillation amplitudes of the oxygen vacancy concentration at the pore/solid interface and within the solid bulk. Moreover, our results demonstrate that the effective tortuosity is dependent on the frequency of the applied AC load as well as the material properties, and thus the prevalent practice of treating tortuosity as a constant for a given cathode should be revised. Finally, we propose a method of determining the aforementioned dependence of tortuosity on material properties and frequency by using the EIS data.

Optimization of rGO-PEI/Naph-SH/AgNWs/Frt/GOx nanocomposite anode for biofuel cell applications

The present study reports a new nanocomposite design using surface modified silver nanowires decorated on the surface of polyethyleneimine (PEI), a cationic polymer acting as glue for anchoring nanowires and reduced graphene oxide (rGO). The synthesized nanocomposite was employed as a promising electrode material for immobilization of biomolecules and effective transportation of electron, in enzymatic biofuel cell (EBFCs) application. The synthesized nanocomposite was confirmed by analytical techniques, for instance, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The electrochemical behaviour of the nanobioelectrocatalysts rGO-PEI/Frt/GOx, rGO-PEI/AgNWs/Frt/GOx, and rGO-PEI/Naph-SH/AgNWs/Frt/GOx was determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). The maximum current density obtained by the modified bioanode was found to be 19.9 mA cm⁻² at the limiting glucose concentration of 50 mM in PBS (pH 7.0) as supporting electrolyte at a scan rate of 100 mVs⁻¹.

Green synthesis of ZnO nanoparticles decorated on polyindole functionalized-MCNTs and used as anode material for enzymatic biofuel cell applications

Presently, one of the most important aspects for the development of enzymatic biofuel cells (EBFCs) is to synthesize the novel electrode materials that possess high current density, low open-circuit voltage (OCV) and long-term stability. To achieve the above attributes, lots of new strategies are being used by the researchers for the development of advanced materials. Nowadays, nanomaterials and nanocomposites are the promising material that has been utilized as effective electrode material in solar cells, supercapacitors and biofuel cells application. Herein, we account for a novel electrocatalyst as electrode material that comprised ZnO nanoparticles decorated on the surface of polyindole (PIn)-multi-walled carbon nanotube (MWCNT), for the immobilization of glucose oxidase (GOx) enzyme and mediator (Ferritin). The PIn-MWCNT scaffold is prepared via in situ chemical oxidative polymerization of indole on the surface of MWCNT and assessed by myriad techniques. The micrograph of scanning electron microscopy (SEM) designated the interconnected morphology of MWCNTs in the polymer matrix. X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FTIR), confirm the crystallinity and different functional groups available in the synthesized material, respectively. The electrochemical assessment demonstrates that the ZnO/PIn-MWCNT/Frt/GOx nanobiocatalyst exhibits much higher electrocatalytic activity towards the oxidation of glucose with a maximum current density of 4.9 mA cm-2 by consuming 50 mM glucose concentration in phosphate buffer saline (PBS) (pH 7.4) as the testing solution by applying 100 mVs-1 scan rates. The outcomes reflect that the as-prepared ZnO/PIn-MWCNTs/Frt/GOx biocomposite is a promising bioanode for the development of EBFCs.