Fig. 1

Preparation and characterization of hydrogen-substituted graphdiyne-based materials. a Schematic illustration of the preparation process for the hydrogen-substituted graphdiyne (HsGDY) from the monomer triethynylbenzene. Triethynylbenzene molecules are polymerized to generate HsGDY through a cross-coupling reaction with copper ion as catalyst. The HsGDY is pyrolyzed in an ammonia (NH₃) atmosphere to produce pyridinic nitrogen-doped hydrogen-substituted graphdiyne (N-HsGDY). For clarity, HsGDY and N-HsGDY are shown with only two layers. b ¹³C solid-state NMR spectrum for HsGDY; the insert displays the structure of the monomer of HsGDY. c Fourier transform infrared spectrum of the HsGDY, d scanning electron microscopy (SEM) and e transmission electron microscopy (TEM) images of HsGDY. f SEM and g TEM images of N-HsGDY-900 °C. Scale bar, 100 nm for d–g