[21a-P01-1~7] 1.1 Interdisciplinary and General Physics

▲ [21a-P01-4] Synthesis Of N Doped Carbon Nanostructures On Stainless Steel And Its Effect On Morphology And Electrochemical Properties

〇Bhagyashri Pramod Todankar¹, Pradeep Desai¹, Ajinkya Ranade¹, Yazid Yaakob^1,3, Toru Asaka¹, Tharangattu Narayanan², Golap Kalita¹, Masaki Tanemura¹ (1.Nagoya Inst. Of Tech, 2.TIFR, Hyderabad, Ind, 3.Universiti Putra,Mal)

Keywords:Supported catalysts, Electrocatalytic properties, Carbon nanomaterials

Introduction: In comparison to existing earth abundant transition metal alloys, stainless steel has been recognized as an excellent water splitting catalyst which, when used in synthesis along with low-dimensional carbon materials, forms substrate supported catalyst. In this regard, we report the synthesis of nitrogen doped carbon nanostructures (CNS) on SUS304 and the effects on its structure and electrocatalytic properties. We observed lower overpotential values for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to alloy particles within the nanostructures.Experimental & Results: Nitrogen doped CNS were synthesized in an atmospheric pressure chemical vapor deposition (APCVD) system on SUS304 foil. In growth duration of 1 h, the precursor temperature was set to 450 °C for 15 mins, then raised to 500 °C for an additional 15mins and finally set to 600 °C for the remaining 30 mins. The resultant CNS (4 mg) were used for ink preparation and electrochemical analyses using a three-electrode system.¹ The ORR and OER analyses were performed in an O₂ saturated 0.1M KOH electrolyte while the HER analysis was performed in an N₂ saturated 0.5M H₂SO₄ electrolyte. Figure 1(a) shows the FE-SEM image of CNS with Cr₂O₃ beads on its outer walls which assisted in lowering the onset potential of ORR (0.88 V with respect to RHE and only 100 mV less than Pt/C). Figure 1(b) shows the TEM image of Cr₂O₃ presenting the effect on the morphology due to synthesis of carbon nanostructures on steel. Figure 1(c) shows the CV for OER and ORR for the same catalyst in 0.1M KOH solution, presenting good oygen evolution with an onset potential of 1.59 V with enhanced current density due to stainless metal particles within the CNS. The HER mechanism also exhibited lower overpotential values but with an onset potential similar to N doped CNFs.