Magnetite nanoparticle anchored graphene cathode enhances microbial electrosynthesis of polyhydroxybutyrate by Rhodopseudomonas palustris TIE-1
Magnetite nanoparticle anchored graphene cathode enhances microbial electrosynthesis of polyhydroxybutyrate by Rhodopseudomonas palustris TIE-1
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DOI：
10.1088/1361-6528/abbe58
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发表时间：
2020-10
期刊：
影响因子：
3.5
通讯作者：
K. Rengasamy;T. Ranaivoarisoa;W. Bai;A. Bose
中科院分区：
文献类型：
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作者：
K. Rengasamy;T. Ranaivoarisoa;W. Bai;A. Bose
微生物电合成（MES）是一项新兴技术，它可以利用阴极提供的电子将二氧化碳（CO2）转化为增值的有机碳化合物。然而，由于微生物对细胞外电子的吸收有限，MES受到低产物形成的影响。本文采用化学合成的磁铁矿纳米颗粒和还原氧化石墨烯纳米复合材料（rGO-MNPs）制备了一种新型阴极。该纳米复合材料被电化学沉积在碳毡（CF/rGO-MNPs）上，并被用作MES生产的阴极。在阴极修饰和未修饰的反应器中测定了由palustris红假单胞菌TIE-1 （TIE-1）产生的生物塑料聚羟基丁酸酯（PHB）。结果表明，磁铁矿纳米颗粒锚定的石墨烯阴极（CF/rGO-MNPs）具有更高的PHB产量（91.31±0.9 mg l−1）。这比未改性的碳毡（CF）高4.2倍，比以前报道的使用石墨的高20倍。该改性阴极将电子吸收增强到−11.7±0.1 μA cm−2，比CF阴极（−2.3±0.08 μA cm−2）高约5倍。改性阴极的法拉第效率比未改性阴极高约2倍。电化学分析和扫描电镜显示，rGO-MNPs促进了TIE-1对电子的吸收，并改善了PHB的产生。总体而言，纳米复合材料（rGO-MNPs）阴极改性提高了MES效率。
Microbial electrosynthesis (MES) is an emerging technology that can convert carbon dioxide (CO2) into value-added organic carbon compounds using electrons supplied from a cathode. However, MES is affected by low product formation due to limited extracellular electron uptake by microbes. Herein, a novel cathode was developed from chemically synthesized magnetite nanoparticles and reduced graphene oxide nanocomposite (rGO-MNPs). This nanocomposite was electrochemically deposited on carbon felt (CF/rGO-MNPs), and the modified material was used as a cathode for MES production. The bioplastic, polyhydroxybutyrate (PHB) produced by Rhodopseudomonas palustris TIE-1 (TIE-1), was measured from reactors with modified and unmodified cathodes. Results demonstrate that the magnetite nanoparticle anchored graphene cathode (CF/rGO-MNPs) exhibited higher PHB production (91.31 ± 0.9 mg l−1). This is ∼4.2 times higher than unmodified carbon felt (CF), and 20 times higher than previously reported using graphite. This modified cathode enhanced electron uptake to −11.7 ± 0.1 μA cm−2, ∼5 times higher than CF cathode (−2.3 ± 0.08 μA cm−2). The faradaic efficiency of the modified cathode was ∼2 times higher than the unmodified cathode. Electrochemical analysis and scanning electron microscopy suggest that rGO-MNPs facilitated electron uptake and improved PHB production by TIE-1. Overall, the nanocomposite (rGO-MNPs) cathode modification enhances MES efficiency.