Fig. 2
From: Selectively nitrogen-doped carbon materials as superior metal-free catalysts for oxygen reduction
Structural information for pyridinic nitrogen-doped hydrogen-substituted graphdiyne. a Nitrogen adsorption/desorption isotherms for all of the pyridinic nitrogen-doped hydrogen-substituted graphdiyne (N-HsGDY) catalysts. b–e High-resolution X-ray photoelectron spectroscopy (XPS) spectra of N 1s for N-HsGDY treated at 700 °C (N-HsGDY-700 °C) (b), N-HsGDY treated at 800 °C (N-HsGDY-800 °C) (c), N-HsGDY treated at 900 °C (N-HsGDY-900 °C) (d), and N-HsGDY treated at 1000 °C (N-HsGDY-1000 °C) (e). f The experimental and calculated curves of N K-edge X-ray absorption near-edge structure (XANES) spectra for N-HsGDY-900 °C
