Rational design and synthesis of hollow Fe–N/C electrocatalysts for enhanced oxygen reduction reaction

Lu²,

et al. 2022

Electroanalysis

N-doped transition metal oxides are strategic materials towards the efficient oxygen reduction reaction (ORR) of microbial fuel cells (MFCs). Non-precious Ndoped Fe 3 O 4 /CoO@NCÀ T (T represents carbonization temperature) catalysts are prepared by an efficient twostep strategy for ORR. Fe 3 O 4 /CoO@NC-750 exhibits the best performance with an efficient four-electron transfer pathway. The optimal power density of MFCs by using Fe 3 O 4 /CoO@NC-750 as the cathode catalyst (1243.4 mW • m À 2 ) is superior to that of the MFCs with commercial Pt/C catalyst (1080 mW • m À 2 ), which shows an outstanding activity towards ORR. No significant decrease in output voltage results over 70 days, which shows an excellent electrochemical stability.

Section: Xpsmentioning

confidence: 98%

Synthesis of Non‐precious N‐doped Mesoporous Fe₃O₄/CoO@NC Materials towards Efficient Oxygen Reduction Reaction for Microbial Fuel Cells

Lu²,

et al. 2022

Electroanalysis

“…It is widely reported that Fe−N−C can effectively reduce the ORR overpotential, improve the reaction kinetics, and increase the ORR activity [9] . So, Fe−N−C is also an excellent electrocatalytic material suitable for MFC cathode [10] …”

Section: Introductionmentioning

confidence: 99%

“…[9] So, FeÀ NÀ C is also an excellent electrocatalytic material suitable for MFC cathode. [10] In the single-chamber MFC, the cathode driving the ORR and the anode to which the bacteria attach are in the same electrolyte environment due to the absence of proton exchange membrane isolation. After the long-term operation, the bacteria on the MFC anode will spread to the cathode, and a biofilm will gradually adhere to the cathode surface, causing biological contamination.…”

Section: Introductionmentioning

confidence: 99%

Two‐Dimensional Ag−Fe−N/C Nanosheets as Efficient Cathode Catalyst to Improve Power‐Generation Performance of Microbial Fuel Cells

et al. 2022

Self Cite

Microbial fuel cells (MFC) are expected to alleviate the energy crisis and environmental pollution. However, both the slow oxygen reduction reaction (ORR) kinetics and the formation of biofilm on the cathode prevent the efficient operation of MFC. Herein, zeolitic imidazole framework (ZIF)‐derived Ag−Fe−N/C catalysts with good electrocatalytic activity are developed by a synthetic strategy of chemisorption, calcination, and photo‐deposition. The optimal Ag−Fe−N/C‐2 has a half‐wave potential (E1/2) of 0.87 V vs. RHE in 0.1 M KOH. The MFC assembled as a cathode exhibits excellent power generation with a maximum power density of 523±7 mW m−2 and long‐term stability, which is better than commercial Pt/C. In addition, the Ag−Fe−N/C‐2 catalyst has the antibacterial ability, which affects the microbial community structure on the cathode biofilm. The results indicate that Ag−Fe−N/C as a bifunctional cathode catalyst with excellent electrocatalytic and antibacterial activity is beneficial to the efficient and long‐term stable operation of MFC.

“…In the last few decades, several concepts and precursors have been utilized to develop many advanced non-precious metal catalysts that show enhanced activity towards the electrochemical reduction of oxygen in both alkaline and acidic media. These materials include metal-organic frameworks [19][20][21][22], conductive-polymer-based complexes (pyrolyzed and non-pyrolyzed) [23,24], non-pyrolyzed transition metal macrocycles [25,26], materials based on metal oxides/carbides/nitrides [27,28], and heat-treated and untreated metal-nitrogen-carbon catalysts [29][30][31]. Recently, a curious approach emerged regarding transition metal-nitrogen-carbon electrocatalytic materials derived from the thermal decomposition of hexacyanometallates, where a carbon-nitrogen-based matrix coordinates metal centers [16,[32][33][34][35][36].…”

Section: Introductionmentioning

confidence: 99%

The Effect of an External Magnetic Field on the Electrocatalytic Activity of Heat-Treated Cyanometallate Complexes towards the Oxygen Reduction Reaction in an Alkaline Medium

et al. 2022

This work focuses on the development of an electrocatalytic material by annealing a composite of a transition metal coordination material, iron hexacyanoferrate (Prussian blue) immobilized on carboxylic-acid-functionalized reduced graphene oxide. Pyrolysis at 500 °C under a nitrogen atmosphere formed nanoporous core–shell structures with efficient activity, which mostly included iron carbide species capable of participating in the oxygen reduction reaction in alkaline media. The physicochemical properties of the iron-based catalyst were elucidated using transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, and various electrochemical techniques, such as cyclic voltammetry and rotating ring–disk electrode (RRDE) voltammetry. To improve the electroreduction of oxygen over the studied catalytic material, an external magnetic field was utilized, which positively shifted the potential by ca. 20 mV. The formation of undesirable intermediate peroxide species was decreased compared with the ORR measurements without an external magnetic field.