Abstract In this study, the performances of NiCo2O4, CoNiAl-LDH, and CoNiAl-LDH@NiCo2O4 were investigated as the catalysts of cathodic reaction in an MFC, for the first time. The synthesized catalysts were characterized by FESEM, XRD, EDX, and DLS techniques. The electrophoretic deposition method was used to immobilize the catalysts on the graphite electrode. The modified electrodes were applied as the cathode of an MFC to compare their output voltage and maximum power density. CoNiAl-LDH electrode had the highest maximum voltage (411.6 mV) and power density (87.91 mW m−2). CoNiAl-LDH@NiCo2O4-modified electrode showed similar results for maximum voltage (405.6 mV) and power density (85.28 mW m−2), however, it had a stable period of maximum voltage equal to 93.66 h. Cyclic Voltammetry results showed that CoNiAl-LDH@NiCo2O4-modified graphite was more electroactive than the others as it produced the highest current density of the redox peaks. Nyquist plots were used to find the equivalent circuit. They showed that the charge transfer and the diffusion resistances of all the modified electrodes significantly decreased compared with the bare graphite.

中文翻译：

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NiCo2O4、CoNiAl-LDH和CoNiAl-LDH@NiCo2O4作为MFC正极ORR催化剂的性能比较

摘要 本研究首次研究了NiCo2O4、CoNiAl-LDH和CoNiAl-LDH@NiCo2O4作为MFC阴极反应催化剂的性能。通过FESEM、XRD、EDX和DLS技术对合成的催化剂进行了表征。采用电泳沉积法将催化剂固定在石墨电极上。修改后的电极用作 MFC 的阴极，以比较它们的输出电压和最大功率密度。CoNiAl-LDH 电极具有最高的最大电压 (411.6 mV) 和功率密度 (87.91 mW m-2)。CoNiAl-LDH@NiCo2O4 修饰电极在最大电压 (405.6 mV) 和功率密度 (85.28 mW m-2) 方面表现出相似的结果，然而，它的最大电压稳定期等于 93.66 h。循环伏安法结果表明，CoNiAl-LDH@NiCo2O4 改性石墨比其他石墨具有更高的电活性，因为它产生最高的氧化还原峰电流密度。奈奎斯特图用于找到等效电路。他们表明，与裸石墨相比，所有改性电极的电荷转移和扩散电阻均显着降低。