| 1. |
- Dai, Junxi, et al.
(författare)
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Promoted Sb removal with hydrogen production in microbial electrolysis cell by ZIF-67-derived modified sulfate-reducing bacteria bio-cathode
- 2023
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Ingår i: Science of the Total Environment. - : ELSEVIER. - 0048-9697 .- 1879-1026. ; 856
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Tidskriftsartikel (refereegranskat)abstract
- Bio-cathode Microbial electrolysis cell (MEC) has been widely discovered for heavy metals removal and hydrogen production. However, low electron transfer efficiency and heavy metal toxicity limit MEC treatment efficiency. In this study, ZIF-67 was introduced to modify Sulfate-reducing bacteria (SRB) bio-cathode to enhance the bioreduction of sulfate and Antimony (Sb) with hydrogen production in the MEC. ZIF-67 modified bio-cathode was developed from a bio-anode microbial fuel cell (MFC) by operating with an applied voltage of 0.8 V to reverse the polarity. Cyclic voltammetry, linear sweep voltammetry and electrochemical impedance were done to confirm the performance of the ZIF67 modified SRB bio-cathode. The synergy reduction of sulfate and Sb was accomplished by sulfide metal precipitation reaction from SRB itself. Maximum sulfate reduction rate approached 93.37 % and Sb removal efficiency could reach 92 %, which relies on the amount of sulfide concentration generated by sulfate reduction reaction, with 0.923 +/- 0.04 m(3) H-2/m(3) of hydrogen before adding Sb and 0.857 m(3) H-2/m(3) of hydrogen after adding Sb. The hydrogen was mainly produced in this system and the result of gas chromatography (GC) indicated that 73.27 % of hydrogen was produced. Meanwhile the precipitates were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy to confirm Sb2S3 was generated from Sb (V).
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| 2. |
- Huang, Linzhe, et al.
(författare)
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Facile synthesis of NS@UiO-66 porous carbon for efficient oxygen reduction reaction in microbial fuel cells
- 2022
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Ingår i: Journal of Power Sources. - : ELSEVIER. - 0378-7753 .- 1873-2755. ; 544
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Tidskriftsartikel (refereegranskat)abstract
- Exploiting a facile way to synthesize low-cost and high-performance oxygen reduction reaction (ORR) catalysts is a core issue in microbial fuel cells (MFCs). Hence, a facile and extensible method has been developed to prepare efficient ORR catalysts by using robust UiO-66 as a precursor, modified with melamine and trithiocyanuric via the impregnation method. Benefiting from the hierarchical structure of UiO-66, the NS@UiO-66 has excellent stability, more active sites and improved mass transfer. Significantly, the half-wave potential and the current density of the NS@UiO-66 are 0.546 V vs. RHE and 6.19 mA cm(-2) respectively, which is better than that of benchmark Pt/C in neutral conditions. Furthermore, the power density of MFCs assembled with the NS@UiO-66 catalyst is 318.6 +/- 2.15 mW m(-2). The density functional theory calculation demonstrates that the reaction barrier can be reduced effectively for accelerating the ORR process through the synergistic effect of N and S. The NS@UiO-66, as an ideal candidate to substitute for the commercial Pt/C counterpart, is expected to promote the scaling-up production and application of MFCs due to low-cost elements doping and facilely synthetic method.
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| 3. |
- Li, Han, et al.
(författare)
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A co-doped oxygen reduction catalyst with FeCu promotes the stability of microbial fuel cells
- 2022
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Ingår i: Journal of Colloid and Interface Science. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0021-9797 .- 1095-7103. ; 628, s. 652-662
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Tidskriftsartikel (refereegranskat)abstract
- Air cathode microbial fuel cell (AC-MFC) cannot be used on a large scale because of its low oxygen reduction reaction (ORR) efficiency. Despite the fact that bimetallic catalysts can greatly enhance the oxygen reduction rate by regulating the electronic structure of the active site, the flaws of insufficient exposure of the active site and easy metal agglomeration limit its catalytic activity. Herein, we report on the preparation of a stable heteroatomic substrate using a copper material organic framework as a precursor, covered by Fe-based active sites. As a result of dipole-dipole interactions, the reduced product Fe2+ forms a weak Fe-O surface that is conducive to the adsorption of active substances. The presence of Fe-0 enhances the electrical conductivity of the catalytic, thus promoting ORR efficiency. Through redox coupling, the D -band center of Fe at FeCu@CN is optimized and brought close to the Fermi level to facilitate electron transfer. Notably, FeCu@CN demonstrates a superior power density of 2796.23 +/- 278.58 mW m(-3), far exceeding that of Pt/C (1363.93 +/- 102.56 mW m(-3)), in the application of microbial fuel cells (MFCs). Meanwhile, the MFC-loaded FeCu@CN maintains excellent stability and outstanding output voltage after 1000 h, which provides feasibility for large-scale application. (C) 2022 Elsevier Inc. All rights reserved.
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| 4. |
- You, Henghui, et al.
(författare)
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Novel Strontium/Iron Bimetallic Carbon Composites as Synergistic Catalyst for Oxygen Reduction Reaction in Microbial Fuel Cells
- 2021
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Ingår i: Electrocatalysis. - : SPRINGER. - 1868-2529 .- 1868-5994. ; 12:6, s. 759-770
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Tidskriftsartikel (refereegranskat)abstract
- It is critical to develop non-noble metal (NNM) electrocatalysts with excellent stability and innovative activity for oxygen reduction reaction (ORR) in the microbial fuel cells (MFCs), which is a promising energy conversion technology. Herein, the preparation of iron carbide electrocatalysts (SrCO3/Fe3C) by the pyrolysis of a bimetal precursor (Sr and Fe) is proposed as a feasible strategy to realize a highly active electrocatalyst for ORR. Based on the catalytic potential of Sr-based materials, Fe species doping can provide more beneficial active sites for ORR. Concisely, the SrCO3/Fe3C(1:12) catalyst achieves the onset potential of 0.197 V (vs. Ag/AgCl) superior than Pt/C catalyst (0.193 V vs. Ag/AgCl) and the half-wave potential of -0.157 V (vs. Ag/AgCl) in 0.1-M KOH solution. Furthermore, the electrocatalyst exhibits nearly four-electron pathway, and generates less than 3% H2O2. Compared with Pt/C catalyst, it possesses preferable stability and superior methanol tolerance. Moreover, a composite electrode with SrCO3/Fe3C(1:12) as a catalyst on the carbon cloth demonstrated a superb air cathode in MFCs with a power density of 398.98 mW m(-2), which can outperform than 10 wt% Pt/C catalysts (342.13 mW m(-2)) on MFCs.
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| 5. |
- Zhang, Hongguo, et al.
(författare)
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Rational design of porous Fex-N@MOF as a highly efficient catalyst for oxygen reduction over a wide pH range
- 2023
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Ingår i: Journal of Alloys and Compounds. - : ELSEVIER SCIENCE SA. - 0925-8388 .- 1873-4669. ; 944
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Tidskriftsartikel (refereegranskat)abstract
- The oxygen reduction reaction (ORR) kinetics are well known to strongly rely on the activives of electro-catalysts. Herein, a Fe-N-doped porous carbon-based electrocatalyst combined with zinc (Zn)-based metal-organic frameworks (MOFs) (Fex-N@MOF) was designed and successfully fabricated via a facile process combined immersion doping and pyrolysis. By controlling the formation of Fe3C, the physical structure of porous carbon was significantly altered, and the active chemical sites of Fe species can be formed to catalyze ORR. The uniform N-doped three-dimensional interpenetrating network structure yielded a high surface area. Both Fe3C and Fe-Nx could offer an abundance of active sites and thus promoted Fe0.05-N@MOF to exhibit high ORR activity in alkaline, neutral and acid electrolytes. Fe0.05-N@MOF showed extraordinary stability and methanol tolerance under a varied pH range conditions, it could be applied as cathode elec-trocatalyst in different fuel cells such as Zn-air fuel cell (ZFC), microbial fuel cells (MFCs), as well as direct methanol fuel cell (DMFC). Fe0.05-N@MOF is a promising material to replace Pt-based electrocatalysts as non-precious metal catalysts.(c) 2023 Elsevier B.V. All rights reserved.
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| 6. |
- Zhong, Kengqiang, et al.
(författare)
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Enhanced oxygen reduction upon Ag/Fe co-doped UiO-66-NH2-derived porous carbon as bacteriostatic catalysts in microbial fuel cells
- 2021
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Ingår i: Carbon. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0008-6223 .- 1873-3891. ; 183, s. 62-75
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Tidskriftsartikel (refereegranskat)abstract
- As a promising energy storage/conversion technology, the microbial fuel cell (MFC) is generally restricted by the biofouling on the cathode and the sluggish kinetics of oxygen reduction reaction (ORR). Consequently, developing bacteriostatic and high-performance ORR catalysts is critical for the large-scale application of MFC. Herein, we prepare an electrocatalyst of porous octahedral zirconium-based metal organic framework (MOF) UiO-66-NH2 with dispersed Ag and Fe3C nanoparticles (Ag/Fe-N-C) through a facile impregnation and pyrolysis method for an efficient alkaline and neutral ORR. Systematic experimental results demonstrate that the synergistic effect of Ag and Fe can optimize the d-band center of catalyst to boost the interfacial charge transfer, thus resulting in an increased ORR kinetics. As expected, the catalyst with Ag/Fe-N-C-2:1 exhibits outstanding onset potential (1.01 V vs. RHE) and half-wave potential (0.58 V vs. RHE) in neutral electrolyte, which is comparable to Pt/C catalyst. Meanwhile, Ag/Fe-N-C-2:1 indicates obvious antibacterial activity, inhibiting the biofouling on the cathode surface. The MFC with the Ag/Fe-N-C-2:1 as the cathode catalyst can achieve a maximum power density of 1261.1 +/- 24 mW m(-3), outperforms the MFC with Pt/C (1087.5 +/- 14 mW m(-3)). In summary, Ag/Fe-N-C2:1 composite can serve as a feasible alternative cathode catalyst for MFC. (C) 2021 Elsevier Ltd. All rights reserved.
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