▎ 摘　　要

A bio-material. hemin, was heat-treated and used as an oxygen reduction reaction (ORR) electrocatalyst. In addition to heat-treatment, two methods were used to improve the catalysts' electrochemical activity. First, high surface area graphene nanoplatelets (GNP) were chosen as a catalyst support. Second, ultrasound was used to break the catalyst samples into smaller pieces. Hemin supported on GNP and heat-treated at 600 degrees C showed significantly higher catalytic activity than those without ultrasonic treatment. Furthermore, a single fuel cell fabricated with the synthesized catalyst yielded a power density of 300 mW cm(-2). Published by Elsevier B.V.