Fig. 4From: A Highly Nanoporous Nitrogen-Doped Carbon Microfiber Derived from Bioresource as a New Kind of ORR ElectrocatalystHigh-resolution N1s XPS spectra of CF-900 (a), CFZ-900 (b), and Me-CFZ-900 (c). (d) High-resolution C1s XPS spectra of Me-CFZ-900 (d)Back to article page