PORPHYRIN APPENDED NANOMATERIALS AND THEIR ELECTROCATALYTIC AND SENSING APPLICATIONS

Abstract

The continuous rise in air pollution day by day is causing devastating effects on living beings. Therefore, to improve the current lifestyle and to ensure a healthy environment for future generations it has become very important to switch towards renewable energy resources such as biofuels, and hydrogen fuels, harnessing solar or wind energy, etc. To achieve this goal researchers are boosting the development of various types of renewable energy technologies such as fuel cells, microbial fuel cells, metal-air batteries, etc. For developing advanced fuel cells, the replacement of expensive Pt-C catalysts with efficient and costeffective catalysts has become essential for better oxygen reduction reaction (ORR) activity. To achieve this, we have synthesized a nanoconjugate iron(II) porphyrin (Fe-MAPP) appended on an aminefunctionalized multi-walled carbon nanotube as an effective and stable electrocatalyst. Further characterization was done by UV-visible spectroscopy, FL spectroscopy, FTIR, FESEM, HRTEM, powder XRD, and TGA. Next, the ORR activity of the nanoconjugate was checked in a basic medium it was observed that the ORR onset potential of nanoconjugates coated on a glassy carbon electrode is comparable with that of a state-of-art catalyst. Also, our nanoconjugate showed a better ORR peak at 0.78 V as compared to the iron(II) porphyrin and MWCNT separately which were at 0.35 V and 0.68 V respectively. This proves that ORR activity was enhanced by combining porphyrin and carbon nanotube. Nanoconjugate as an electrocatalyst also showed methanol tolerance i.e., the ORR current density and onset potential remained unchanged upon the addition of 3M methanol. Thus, the above studies confirm the nanoconjugate's stability and efficient ORR activity.