Bridging N-doped graphene and carbon rich C3N4 layers for photo-promoted multi-functional electrocatalysts

Abstract Distinctive electronegativity and similar atomic radius for elements of C and N afford their allotropic substances composed of these two elements with excellent photo- and electro-chemical performance for energy conversion. To explore the synergetic roles of allotropic substances, carbon-rich C 3 N 4 (CCN) is in - situ hydrothermally synthesized with the N-doped graphene (NG) grown by chemical vapor deposition (CVD) as the template to prepare the N-doped graphene/carbon-rich C 3 N 4 composite. Compared to the N-doped graphene and carbon-rich C 3 N 4 , N-doped graphene/carbon-rich C 3 N 4 composite exhibits the remarkable enhancement of catalytic activities toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Particularly, visible light irradiation can significantly improve the catalytic performance of N-doped graphene/carbon-rich C 3 N 4 toward the above three reactions. Further results confirm that N-doped graphene/carbon-rich C 3 N 4 exhibits the improved electrochemically active surface area (ECSA), light-harvesting ability, effective separation of electron-hole pairs, and interfacial charge transfer as compared to the N-doped graphene and carbon-rich C 3 N 4 which should be originated from the efficient bridging between N-doped graphene and carbon-rich C 3 N 4 layers. Our elucidation facilitates to pave their promising applications in microelectronic devices, wearable devices, photoelectrochemical batteries, sensors and other fields.