Synergistic effect of thiourea on tuning CoNi@CNFs catalysts: An efficient and durable catalyst for oxygen reduction reaction

摘要

Thiourea is utilized to tailor the microstructure of electrospinning carbon nanofibers embedded with CoNi alloy nanoparticles (CoNi@CNFs). When adding thiourea to the precursor, the average grain size of CoNi nanoparticles reduced from 19.4 to 10.2 nm. The refining and well-dispersed CoNi nanoparticles leads to a 57% increase in the graphitization degree of CNFs. Meanwhile, thiourea can introduce abundant S doping (1.44 at.%) in CoNi@CNFs. The synergistic effect of thiourea enlarges the exposure of active sites and facilitates the electron transfer of CoNi@CNFs. As a result, the CoNi@CNFs delivers positive half wave potential (0.91 V), high limiting current density (6 mA/cm(2)), superior methanol resistance and stability. (C) 2021 Elsevier B.V. All rights reserved.