A novel graphdiyne (CnH2n−2) preparation strategy: calcium carbide-derived graphdiyne film supported cobalt tetroxide nanoneedles for photocatalytic hydrogen production

Abstract

Guiding the directional and effective migration of photocarriers is a basic strategy to achieve high performance of catalysts in the photocatalytic water splitting process. In this paper, a new carbon material of graphdiyne (GDY) was prepared by a mechanical ball milling method, and then it was introduced into metal oxide Co₃O₄ by an ultrasonic in situ stirring method. The lamellar film structure of GDY provides effective support for Co₃O₄ nanoneedles. It is undeniable that the Co₃O₄/GDY composite has excellent photocatalytic performance for hydrogen production. The highest hydrogen production activity of Co₃O₄/GDY-20 is 2456 μmol g⁻¹, which is 7.7 times that of pure Co₃O₄. In addition, the successful construction of the two-phase S-scheme heterojunction creates favorable conditions for photoelectron migration, and separates the photoelectron–hole pairs successfully. Ultraviolet diffuse reflectance spectra reflect the light absorption capacity of the composite in a wide light wavelength range. Fluorescence spectra and electrochemical detection confirm that photoelectron migration in the composite is effectively regulated, which is very conducive to photocatalytic water splitting. The study shows that the introduction of carbon materials into metal oxides has great potential in the field of photocatalysis.