Bhatti Adeel Liaquat, Aftab Umair, Tahira Aneela, Abro Muhammad Ishaq, Mari Riaz Hussain, Samoon Muhammad Kashif, Aghem Muhammad Hassan, Shaikh Nek Muhammad, Mugheri Abdul Qayoom, Ibupoto Zafar Hussain
Institute of Physics, University of Sindh, Jamshoro, 76080, Sindh Pakistan.
Mehran University of Engineering and Technology, 76080 Jamshoro, Sindh Pakistan.
J Nanosci Nanotechnol. 2021 Apr 1;21(4):2675-2680. doi: 10.1166/jnn.2021.19098.
The design of efficient, stable, durable and noble metal free electro catalysts for oxygen evolution reaction (OER) are of immediate need, but very challenging task. In this study, iron induction into cobalt oxide (Co₃O₄) has resulted composite structure by wet chemical method. The iron impurity has brought an electronic disorder into Fe₃O₄/cobalt oxide composite thereby efficient oxygen evolution reaction is demonstrated. An addition of iron content into composite resulted the alternation of morphology from Nano rods to clusters of nanoparticles. The successive addition of iron into composite system reduced the onset potential of OER as compared to the pristine cobalt oxide. A Tafel slope of 80 mVdec indicates the favorable oxygen evolution reaction kinetics on the sample 4. An over-potential of 370 mV is required to reach a 10 mAcm current density which is acceptable for a nonprecious catalyst. The catalyst is highly durable and stable for 30 hours. Electrochemical impedance spectroscopy further provided a deeper insight on charge transfer resistance and sample 4 has low charge transfer resistance that supported the OER polarization curves. The sample 4 has more electrochemical active surface area of 393.5 cm². These obtained results are exciting and highlighting the importance of composite structure and leave a huge space for the future investigations on composite materials for energy related applications.
设计高效、稳定、耐用且不含贵金属的析氧反应（OER）电催化剂迫在眉睫，但却是一项极具挑战性的任务。在本研究中，通过湿化学方法将铁引入氧化钴（Co₃O₄）中形成了复合结构。铁杂质给Fe₃O₄/氧化钴复合材料带来了电子无序，从而证明了高效的析氧反应。向复合材料中添加铁含量导致形态从纳米棒转变为纳米颗粒簇。与原始氧化钴相比，向复合体系中连续添加铁降低了OER的起始电位。80 mVdec的塔菲尔斜率表明样品4上有利的析氧反应动力学。达到10 mAcm电流密度需要370 mV的过电位，这对于非贵金属催化剂来说是可以接受的。该催化剂在30小时内具有高度的耐久性和稳定性。电化学阻抗谱进一步深入了解了电荷转移电阻，样品4具有低电荷转移电阻，这支持了OER极化曲线。样品4具有393.5 cm²的更大电化学活性表面积。这些结果令人兴奋，突出了复合结构的重要性，并为未来能源相关应用的复合材料研究留下了巨大空间。
