Matibag VKR, Geronimo HGD, Garcia JL, Tongol BJV. Platinum-Free Electrocatalyst for Oxygen Reduction Reaction Derived from the Direct Pyrolysis of Waste Watermelon Peels. ijie. 2019;11(7):175-181. Accessed May 3, 2024. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/4639