Highly active and durable carbon support Pt-rare earth catalyst for proton exchange membrane fuel cell

Pt-rare earth catalysts are highly efficient novel electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) due to their high stability and activity. In this study, we prepare Pt-YO_x/C catalysts using the traditional wet chemical reduction method. The optimal quantity of Y-oxides loaded onto the Pt/C surface is determined based on electrochemical performance using linear sweep voltammetry (LSV) and cyclic voltammetry (CV) methods. After accelerated durability tests (ADT), the remnant electrochemical surface area (ECSA) and mass active (MA) in Pt-YO_x/C catalyst are relatively higher compared to the commercial Pt/C (JM). In the single-cell test, the maximum mass power densities of the MEAs prepared by self-made Pt-YO_x/C and Pt/C (JM) catalysts in cathodes record at 1895 and 1371 mW mg_Pt⁻¹, respectively, which shows a successful increment in platinum utilization. These results indicate that Pt-YO_x/C catalyst can potentially improve the durability and lower the cost of PEMFCs.     

Effect of Pt–Pd/C coupled catalyst loading and polybenzimidazole ionomer binder on oxygen reduction reaction in high-temperature PEMFC

Polybenzimidazole (PBI) was studied as an ionomer binder at varying ratios (1–7) in a 20–40 wt% Pt–Pd/C cathode-coupled catalyst layer for the oxygen reduction reaction (ORR) in a high-temperature proton exchange membrane fuel cell (HT-PEMFC). Catalytic activity was examined by CV and LSV, while the properties of the catalysts were characterized by FESEM-EDX, N₂ adsorption–desorption, XRD and FTIR. The results showed that the distribution of metals on the carbon surface, carbon wall thickness and the interaction between ionomer and coupled catalysts affected the ORR performance. The fabricated membrane electrode assembly with 5:95 PBI: 30 wt% Pt–Pd/C catalyst ratio exhibited the best performance and highest durability for HT-PEMFC at 170 °C, yielding a power density of 1.30 Wcm⁻² with 0.02 mg_Pt/cm Pt loading. This performance of ultra-low metal loading of coupled Pt–Pd/C electrocatalyst with PBI binder was comparable to those reported by other studies, highlighting a promising catalyst for fuel cell application.     

Graphene based catalyst supports for high temperature PEM fuel cell application

In this study, the effect of graphene nanoplatelet (GNP) and graphene oxide (GO) based carbon supports on polybenzimidazole (PBI) based high temperature proton exchange membrane fuel cells (HT-PEMFCs) performances were investigated. Pt/GNP and Pt/GO catalysts were synthesized by microwave assisted chemical reduction support. X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Brauner, Emmet and Teller (BET) analysis and high resolution transmission electron microscopy (HRTEM) were used to investigate the microstructure and morphology of the as-prepared catalysts. The electrochemical surface area (ESA) was studied by cyclic voltammetry (CV). The results showed deposition of smaller Pt nanoparticles with uniform distribution and higher ECSA for Pt/GNP compared to Pt/GO. The Pt/GNP and Pt/GO catalysts were tested in 25 cm² active area single HT-PEMFC with H₂/air at 160 °C without humidification. Performance evaluation in HT-PEMFC shows current densities of 0.28, 0.17 and 0.22 A/cm² for the Pt/GNP, Pt/C and Pt/GO catalysts based MEAs at 160 °C, respectively. The maximum power density was obtained for MEA prepared by Pt/GNP catalyst with H₂/Air dry reactant gases as 0.34, 0.40 and 0.46 W/cm² at 160 °C, 175 °C and 190 °C, respectively. Graphene based catalyst supports exhibits an enhanced HT-PEMFC performance in both low and high current density regions. The results indicate the graphene catalyst support could be utilized as the catalyst support for HT-PEMFC application.     

Power generation using polyaniline/multi‐walled carbon nanotubes as an alternative cathode catalyst in microbial fuel cells

Optimization of the cathode catalyst is critical to the study of microbial fuel cells (MFCs). By using the open circuit voltage and power density as evaluation standards, this study focused on the use of polyaniline (PANI)/multi‐walled carbon nanotube (MWNT) composites as cathode catalysts for the replacement of platinum (Pt) in an air‐cathode MFC, which was fed with synthetic wastewater. Scanning electron microscopy and linear scan voltammogram methods were used to evaluate the morphology and electrocatalytic activity of cathodes. A maximum power density of 476 mW/m² was obtained with a 75% wt PANI/MWNT composite cathode, which was higher than the maximum power density of 367 mW/m² obtained with a pure MWNT cathode but lower than the maximum power density of 541 mW/m² obtained with a Pt/C cathode. Thus, the use of PANI/MWNT composites may be a suitable alternative to a Pt/C catalyst in MFCs. PANI/MWNT composites were initially used as cathodic catalysts to replace Pt/C catalysts, which enhanced the power generation of MFCs and substantially reduced their cost. Copyright © 2014 John Wiley & Sons, Ltd.     

A non-noble V2O5 nanorods as an alternative cathode catalyst for microbial fuel cell applications

This study assessed the feasibility of vanadium pentoxide (V₂O₅) as a novel cathode catalyst material in air-cathode single chamber microbial fuel cells (SCMFCs). The V₂O₅ nanorod catalyst was synthesized using a hydrothermal method. MFCs with different cathode catalyst loadings were studied. Cyclic voltammetry (CV) was used to examine the electrochemical behavior of the catalysts in the MFCs. The V₂O₅ cathode catalyst constructed with a double loading MFC exhibited the highest maximum power density of 1073 ± 18 mW m⁻² (OCP; 691±4 mV) compared with 447 ± 12 mW m⁻² (OCP; 594 ± 5 mV) and 936 ± 15 mW m⁻² (OCP; 647±5 mV) for the single loading MFC and triple loading MFC, respectively. The power density of MFC with double loaded V₂O₅ is comparable to the traditional Pt/C cathode (2067 ± 25 mW m⁻², OCP; 821 ± 4 mV), which covers up to 55% of the performance of Pt/C. This finding highlights the potential of the V₂O₅ cathode as an inexpensive catalyst material for MFCs that may have commercial applications.     

Enhanced electrochemical performance in microbial fuel cell with carbon nanotube/NiCoAl-layered double hydroxide nanosheets as air-cathode

The ternary component NiCoAl-layered double hydroxide (NiCoAl-LDH) and carbon nanotube (CNT) nano-composite (CNT/NiCoAl-LDH) were successfully prepared by a simple hydrothermal method. The NiCoAl-LDH nanosheets were effectively and uniformly grown on CNTs, forming a cross-linked conductive network structure, and stainless steel (SS) mesh was used as the base to load CNT/NiCoAl-LDH for microbial fuel cell (MFC) cathode. X-ray diffraction (XRD) results presented that the CNT/NiCoAl-LDH hybrid exhibited the (003), (006), (012), (015), (018), (110) and (113) crystal planes of hydrotalcite reflection. The surface functional groups C-O, C=O, C-H, C-N and M-O of the hybrid were confirmed. The cross-linked network structure of the hybrid was observed and the content and proportion of each element of the hybrid were found. CNT/NiCoAl-LDH showed excellent catalytic oxygen reduction reaction (ORR) ability by cyclic voltammetry (CV) and linear voltammetry (LSV) due to its abundant electrochemical active sites and excellent conductivity. The maximum output voltage of CNT/NiCoAl-LDH catalyst as MFC cathode was 450 mV, the maximum power density was 433.5 ± 14.8 mW/m², and the maximum voltage stabilization time was 7–8 d. The results indicated that the CNT/NiCoAl-LDH hybrid was full potential as a high-performance, low-cost MFC cathode catalyst in future.     

Highly durable and active non-precious air cathode catalyst for zinc air battery

The electrochemical stability of non-precious FeCo-EDA and commercial Pt/C cathode catalysts for zinc air battery have been compared using accelerated degradation test (ADT) in alkaline condition. Outstanding oxygen reduction reaction (ORR) stability of the FeCo-EDA catalyst was observed compared with the commercial Pt/C catalyst. The FeCo-EDA catalyst retained 80% of the initial mass activity for ORR whereas the commercial Pt/C catalyst retained only 32% of the initial mass activity after ADT. Additionally, the FeCo-EDA catalyst exhibited a nearly three times higher mass activity compared to that of the commercial Pt/C catalyst after ADT. Furthermore, single cell test of the FeCo-EDA and Pt/C catalysts was performed where both catalysts exhibited pseudolinear behaviour in the 12-500 mA cm⁻² range. In addition, 67% higher peak power density was observed from the FeCo-EDA catalyst compared with commercial Pt/C. Based on the half cell and single cell tests the non-precious FeCo-EDA catalyst is a very promising ORR electrocatalyst for zinc air battery.     

Electro-catalytic activity of enhanced CO tolerant cerium-promoted Pt/C catalyst for PEM fuel cell anode

Cerium-promoted Pt/C catalysts were prepared by one-pot synthesis process and applied as an anode material for CO tolerance in PEM fuel cell. Its physical properties were characterized by XRD and TEM techniques, which indicated that Pt nano-particles are highly dispersed on the carbon supports. The investigation focused on examining the CO tolerance in sulfur acid solution of Pt–CeO₂/C compared to Pt/C (JM). The hydrogen oxidation activity was strongly depended on the content of the cerium in the Pt catalyst which was detected by CV, LSV, CO-stripping and EIS techniques. Effect of the anode catalyst poisoning on hydrogen oxidation in the presence of CO was studied in single cells. Pt–CeO₂/C catalyst at the appropriate content of 20% Ce presented a very higher CO tolerant activity. A tentative mechanism is proposed for a possible role of a bi-functional synergistic effect between Pt and CeO₂ for the enhanced electro-oxidation of CO. CeO₂-promoted Pt/C catalyst may be one of the attractive candidates as CO tolerance anode material in PEMFC.     

Kinetics and electrocatalytic activity of IrCo/C catalysts for oxygen reduction reaction in PEMFC

The purpose of this study is to develop a novel binary Iridium-Cobalt/C catalyst as a suitable substitute for platinum/C applied in proton exchange membrane fuel cells (PEMFCs). The carbon-supported IrCo catalysts were successfully synthesized using IrCl₃ and C₄H₆CoO₄ as the Ir and Co precursors respectively, in ethylene glycol (EG) refluxing at 120 °C. The nanostructured catalysts were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscope (TEM). Homogeneous catalyst particles supported on carbon showed a size of proximately 2 nm. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were conducted for the characterization of the catalyst performances. With a cathodic loading of 0.4 mg_Ir cm⁻², 20%Ir-30%Co/C achieved a maximum power density of 501.6 mW cm⁻² at 0.418 V, with a 50 cm² H₂/O₂ single cell. Although such a performance is about 26% lower than commercial Pt/C catalyst, it is still helpful in terms of Pt replacement and cost reduction.     

Effective factors improving catalyst layers of PEM fuel cell

Cathode catalyst layer has an important role on water management across the membrane electrode assembly (MEA). Effect of Pt percentage in commercial catalyst and Pt loading from the viewpoint of activity and water management on performance was investigated. Physical and electrochemical characteristics of conventional and hydrophobic catalyst layers were compared. Performance results revealed that power density of conventional catalyst layers (CLs) increased from 0.28 to 0.64 W/cm² at 0.45 V with the increase in Pt amount in commercial catalyst from 20% to 70% Pt/C for H₂/Air feed. In the case of H₂/O₂ feed, power density of CLs increased from 0.64 to 1.29 W/cm² at 0.45 V for conventional catalyst layers prepared with Tanaka. Increasing Pt load from 0.4 to 1.2 mg/cm², improved kinetic activity at low current density region in both feeding conditions. Scattering electron microscopy (SEM) images revealed that thickness of the catalyst layers (CLs) increases by increasing Pt load. Electrochemical impedance spectroscopy (EIS) results revealed that thinner CLs have lower charge transfer resistance than thicker CLs. Inclusion of 30 wt % Polytetrafluoroethylene (PTFE) nanoparticles in catalyst ink enhanced cell performance for the electrodes manufactured with 20% Pt/C at higher current densities. However, in the case of 70% Pt/C, performance enhancement was not observed. Cyclic voltammetry (CV) results revealed that 20% Pt/C had higher (77 m²/g) electrochemical surface area (ESA) than 70% Pt/C (65 m²/g). In terms of hydrophobic powders, ESA of 30PTFE prepared with 70% Pt/C was higher than 30PTFE prepared with 20 %Pt/C. X-Ray Diffractometer (XRD) results showed that diameter of Pt particles of 20% Pt/C was 2.5 nm, whereas, it was 3.5 nm for 70% Pt/C, which confirms CV results. Nitrogen physisorption results revealed that primary pores of hydrophobic catalyst powder prepared with 70% Pt/C was almost filled (99%) with Nafion and PTFE.     

Pt and Pt–Ag nanoparticles supported on carbon nanotubes (CNT) for oxygen reduction reaction in alkaline medium

In this work, we investigated the effect of the carbon nanotubes (CNT) as alternative support of cathodes for oxygen reduction reaction (ORR) in alkaline medium. The Pt and Pt–Ag nanomaterials supported on CNT were synthesized by sonochemical method. The crystalline structure, morphology, particle size, dispersion, specific surface area, and composition were investigated by XRD, SEM-EDS, TEM, HR-TEM, N₂ adsorption-desorption and XPS characterization. The electrochemical activity for ORR was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) in alkaline medium. The electrochemical stability was researched by an accelerated degradation test (ADT). Pt/CNT showed the better electrocatalytic activity towards ORR compared with Pt–Ag/CNT and Pt/C. Pt/CNT exhibited higher specific activity (1.12 mA cm^?2 _Pt) than Pt/C (0.25 mA cm^?2 _Pt) which can be attributed to smaller particle size, Pt-CNT interaction, and Pt load (5 wt%). The Pt monometallic samples supported on CNT and Vulcan showed higher electrochemical stability after ADT than Pt–Ag bimetallic. The ORR activity of all materials synthesized proceeded through a four-electron pathway. Furthermore, the EIS results showed that Pt/CNT exhibited the lower resistance to the transfer electron compared with conventional Pt/C and Pt–Ag/CNT.     

Carbon supported Pt-shell modified PdCo-core with electrocatalyst for methanol oxidation

A catalyst for anode oxidation of methanol, carbon supported pseudo-core-shell PdCo@Pt particles with Pt shell is prepared via a two-step procedure, which consists of an organic colloid method and a surface replacement reaction step. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) are used for the catalysts characterization. The electrochemical surface areas (ECSA) are 6 and 4 times as large as those of Pt/C and PtRu/C catalysts, respectively. Furthermore, based on the Pt mass, the cyclic voltammetry (CV) and chronoamperometry results demonstrate that the electrocatalytic activity and stability of the PdCo@Pt/C catalyst for methanol oxidation are much higher than those of the Pt/C and PtRu/C catalysts. The PdCo@Pt/C catalyst is better utilization of Pt than pure Pt and Pt-based alloy catalysts.     

Nitrogen doped graphene supported Pd as hydrogen evolution catalyst for electrochemical methanol reformation

Electrochemical methanol reformation (ECMR) method has been identified as one of the most effective method for on-site hydrogen production. However, concentrated research towards the development of efficient inexpensive hydrogen evolution reaction (HER) electrocatalyst holds the pivotal role in realizing the hydrogen economy. In this context, for the first time N-graphene supported Pd (Pd/NG) was synthesised and employed as an HER catalyst in ECMR process. N-graphene was synthesised by modified Hummer's method followed by Pd deposition through hydrothermal route. The electrocatalytic activity of Pd/NG for hydrogen evolution was evaluated by CV and LSV techniques. Tafel slope of Pd/NG and Pt/C was calculated from LSV curves and was found to be 33 and 31 mV/decade, respectively. Exchange current density was found to be 3.6 and 3.2 × 10⁻⁴ A cm⁻² for Pd and Pt catalysts, respectively. The enhanced electrocatalytic activity is majorly attributed to the N-doping and uniform distribution of Pd nano particles on graphene. Further, the performance of Pd/NG was also evaluated in single ECMR cell using Pt–Ru/C at anode and Pd/NG at cathode as electrocatalysts. The results indicated the suitability of Pd/NG as cathode electrocatalyst for HER in ECMR process.     

Carbon-supported Pd-Pt cathode electrocatalysts for proton exchange membrane fuel cells

A series of carbon-supported Pd-Pt alloy (Pd-Pt/C) catalysts for oxygen reduction reaction (ORR) with low-platinum content are synthesized via a modified sodium borohydride reduction method. The structure of as-prepared catalysts is characterized by powder X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The prepared Pd-Pt/C catalysts with alloy form show face-centered-cubic (FCC) structure. The metal particles of Pd-Pt/C catalysts with mean size of around 4-5 nm are uniformly dispersed on the carbon support. The electrocatalytic activities for ORR of these catalysts are investigated by rotating disk electrode (RDE), cyclic voltammetry (CV), single cell measurements and electrochemical impedance spectra (EIS) measurements. The results suggest that the electrocatalytic activities of Pd-Pt/C catalysts with low platinum are comparable to that of the commercial Pt/C with the same metal loading. The maximum power density of MEA with a Pd-Pt/C catalyst, the Pd/Pt mass ratio of which is 7:3, is about 1040 mW cm⁻².     

Effect of metal particle size and Nafion content on performance of MEA using Ir-V/C as anode catalyst

Ir and Ir-V nanoparticles were synthesized in ethylene glycol using IrCl₃ and NH₄VO₃ as the Ir and V precursors, respectively. These nanoparticles were evaluated as anode catalysts in proton exchange membrane fuel cells (PEMFCs). A thermal treatment of the catalysts at 200 °C in a reducing atmosphere leads to very high electrocatalytic activity for the hydrogen oxidation reaction. The fuel cell performance reveals an optimal Nafion ionomer content of 25% in the catalyst layer used for the MEA fabrication. The electrocatalytic effects related to the change in the electrocatalyst structure are discussed based on the data obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques are used in-situ to assess the kinetics of hydrogen oxidation on the surface of these catalysts. A maximum power density of 1016.6 mW cm⁻² was obtained at 0.598 V and 70 °C with an anode catalyst loading of 0.4 mg (Ir) cm⁻². This performance is 50.7% higher than that for commercially available Pt/C catalysts under the same conditions. In addition, we also tested the anode catalyst with a low loading of 0.1 mg (Ir) cm⁻², the maximum power density is 33.8% higher than that of the commercial Pt/C catalyst with a loading of 0.4 mg (Pt) cm⁻².     

Multi-walled carbon nanotubes decorated by platinum catalyst for high temperature PEM fuel cell

In the literature, studies on platinum catalysts deposited on multi-walled carbon nanotube (Pt/MWCNT) have been mostly focused on low temperature fuel cell (LT-PEMFC) applications. In this study, we focus the synthesis and characterization of high temperature fuel cell (HT-PEMFC) performance of Pt/MWCNT in short and long term. The structural properties of the Pt/MWCNT electrocatalyst were analyzed by XRD, TGA, SEM and TEM measurements. The Pt/MWCNTs were also characterized by electrochemical measurements for durability estimation. Laboratory scale MEA with Pt/MWCNT was prepared by ultrasonic coating technique and has been tested in situ in single HT-PEMFC. Performance curves in dry Hydrogen/Air system were obtained that demonstrated performance comparable to commercial catalysts in that HT-PEMFC. The characterizations specified that the electrocatalytic and HT-PEMFC performance of the Pt/MWCNT catalysts are higher power density (0.360 W/cm²) than Pt/C (0.310 W/cm²) at 160 °C. The results obtained show that the synthesized catalysts are suitable for high temperature applications. In addition, the stability studies of MEAs prepared with Pt/MWCNT catalyst were performed by AST tests and compared with Pt/C based MEA.     

Poly (acrylamide-co-acrylonitrile) hydrogel-derived iron-doped carbon foam electrocatalyst for enhancing oxygen reduction reaction in microbial fuel cell

Developing advanced non-precious metal catalysts for oxygen reduction reaction (ORR) is critical for microbial fuel cells (MFCs). Fe–N–C catalysts are considered the best successor to platinum-based catalysts for ORR. Herein, we have synthesized environmental friendly, cost-effective Fe–N-doped carbon foam catalyst [Fe-embedded poly (acrylamide-co-acrylonitrile) hydrogel-based carbon foam(Fe@Am-co-An/CF)] by using Fe-embedded poly (Am-co-An) hydrogel for MFCs. Poly(Am-co-An) hydrogel is used as a carbon and nitrogen precursor. The synthesized catalysts are characterized by FTIR, SEM, TEM, XRD and XPS. Furthermore, four different catalysts based on different ratios of the metal such as Fe@Am-co-An/CF (1:22), Fe@Am-co-An/CF (2:22), Fe@Am-co-An/CF (3:22), and Am-co-An/CF have been prepared. Results indicate that the Fe@Am-co-An/CF (2:22) catalyst exhibits the highest power density (736.06 mWm^?2 at the current density of 1132.04 mAm^?2) compared to the other catalysts. The results of CV, LSV, EIS, and chronoamperometry indicate that Fe@Am-co-An/CF (2:22) is the most promising catalyst for ORR activity in MFCs.     

A new durable and high performance platinum supported on Ag–Ni-porous coordination polymer as an anodic DMFC nano-electrocatalyst: DFT and experimental investigation

Due to the poor performance and intermediates poisoning of available catalysts in direct methanol fuel cells (DMFC), the researcher is confronted with a considerable challenge for obtaining modified electrocatalyst. Ag–Ni porous coordination polymer (ANP) as a new electrocatalyst supporter was synthesized by a hydrothermal method. To achieve favorable electrocatalyst for DMFC systems, platinum nanoparticles was deposited upon ANP by an electrochemical method and platinum supported on Ag–Ni porous coordination polymer (Pt-ANP) was formed. Fourier transform infrared spectroscopy (FTIR) analysis ensured correct synthesized of ANP and Pt-ANP. In addition, the morphologies investigation of ANP and Pt-ANP were carried out by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The FE-SEM images indicate that the platinum nanoparticles have been greatly deposited on ANP surface. Electrochemical behaviors of prepared catalyst for methanol oxidation were evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA) techniques. Electrochemical cyclic voltammetry tests (CV) indicate that the forward peak current density of Pt-ANP is about 105 mA/cm² which it is 33% more than the forward peak current density of pure Pt catalyst (70.21 mA/cm²). Moreover, electrochemical surface area (ECSA) of Pt-ANP is 26.42 m²/g_Pt. In addition, density functional theory (DFT) computations show that with the deposition of Pt upon ANP, the HOMO-LOMO energy gap of ANP has been decreased which they are suitable for electrochemical reactions. Theoretical results are greatly in accordance with the experiments. Based on the results, Pt-ANP could be a superior electrocatalyst for methanol oxidation.     

Bimetallic Pt3Mn nanowire network structures with enhanced electrocatalytic performance for methanol oxidation

Pt-based catalysts are still most attractive and could be the major driving force for facile electrochemical reactions in direct methanol fuel cells (DMFCs). In this work, a Pt₃Mn nanowire network structures (NWNs) catalyst was successfully synthesized by a soft template (CTAB) method. The morphology and elemental composition of the Pt₃Mn NWNs were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). The electrocatalytic behavior of the synthesized Pt₃Mn NWNs catalyst towards methanol oxidation reaction (MOR) was studied by cyclic voltammetry (CV) and chronoamperometry (CA). The results reveal that the Pt₃Mn NWNs has superior MOR activity and durability compared to Pt NWNs and commercial Pt/C. The mass and specific activities of Pt₃Mn NWNs are 0.843 A mg⁻¹ and 1.8 mA cm⁻² respectively, which are twice that of commercial Pt/C. Additionally, the results of CA test indicate that the Pt₃Mn NWNs possesses better durability than Pt NWNs and commercial Pt/C catalysts in acidic media, which is expected to be a new alternative anode material in DMFCs.     

Facile microwave-assisted synthesized reduced graphene oxide/tin oxide nanocomposite and using as anode material of microbial fuel cell to improve power generation

A new nanocomposite material was fabricated by a facile and reliable method for microbial fuel cell (MFC) anode. Tin oxide (SnO₂) nanoparticles were anchored on the surface of reduced graphene oxide (RGO/SnO₂) in two steps. The hydrothermal method was used for the modification of GO and then microwave-assisted method was used for coating of SnO₂ on the modified GO. Nanohybrids of RGO/SnO₂ achieved a maximum power density of 1624 mW m⁻², when used as the MFC anode. The obtained power density was 2.8 and 4.8 times larger than that of RGO coated and bare anodes, respectively. The electrodes were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The electrochemical characteristics were also studied by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The high conductivity and large specific surface of the nanocomposite were greatly improved the bacterial biofilm formation and increased the electron transfer. The results demonstrate that the RGO/SnO₂ nanocomposite was advantageous material for the modification of anode and enhanced electricity generation of MFC.