Materials Science and Engineering

Biography

Biography: Marzia Quaglio

Abstract

This work is focused on the development of N-doped carbon nanofibers (N-CNFs) as catalyst for the oxygen reduction reaction (ORR). In devices for energy storage and production, as microbial fuel cells and li-air batteries, oxygen can be used as the terminal electron acceptor. The overall efficiency of these devices is limited by the low kinetics of the ORR. A catalyst layer must be used, to enhance the direct ORR, ensuring a number of electrons as close as possible to the ideal value of 4. Platinum is currently the best performing catalyst, however its scarcity, limited durability and high-cost, have made necessary to identify efficient substitutes. In this view nanomaterials can play a crucial role for further improvement in this area of catalysis. The development of nonprecious materials as alternative catalysts is among the pursued strategies. Nanostructured non-metal carbon-based materials, especially doped with heteroatoms like nitrogen, have established among the most promising noble metal free alternatives. In this work focus is given to the optimization of N-CNFs, especially in terms of their content of graphitic, pyrrolic and pyridinic nitrogen defects, as well as their high surface area. N-CNFs have been prepared by electrospinning, starting from a polymeric solution of polyacrylonitrile in N,N-dimethylformamide. As fabricated nanofibers were stabilized at 280ºC in air and then thermally treated up to 900ºC under inert atmosphere. X-ray photoelectron spectroscopy confirmed a high content of graphitic nitrogen and a proper amount of pyridinic one in CNFs, leading thus to improve ORR performances. Good electrochemical properties of the samples were established by rotating ring disk electrode (RRDE). An electron transfer number of 3.9 has been obtained for the N-CNFs processed at the higher temperature.

Recent Publications:

1. Delmondo L, Salvador G P, Muñoz-Tabares J A, Sacco A, Garino, N, Castellino M, Gerosa M, Massaglia G, Chiodoni A, Quaglio M (2016) Nanostructured Mn_xO_y for oxygen reduction reaction (ORR) catalysts. Applied Surface Science 388: 631-639.

2. Garino N, Sacco A, Castellino M, Muñoz-Tabares J A, Chiodoni A, Agostino V, Margaria V, Gerosa M, Massaglia G, Quaglio M (2016) Microwave-assisted synthesis of reduced graphene oxide/SnO₂ nanocomposite for oxygen reduction reaction in microbial fuel cells. ACS Applied Materials & Interfaces 8: 4633.