Mechanochemical preparation and application of graphdiyne coupled with CdSe nanoparticles for efficient photocatalytic hydrogen production

Abstract

Graphdiyne (GDY) has attracted considerable attention as a new two-dimensional (2D) carbon hybrid material because of its good conductivity, adjustable electronic structure, and special electron transfer enhancement properties. GDY has great potential in the field of photocatalytic water splitting for hydrogen evolution, owing to its unique properties. In this study, GDY was successfully prepared by the mechanochemical coupling of precursors C6Br6 and CaC2 using a ball-milling approach. The prepared GDY, especially its microstructure and composition, was well characterized using different techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared, and Raman characterization techniques. By exploiting the unique two-dimensional (2D) structure and outstanding light absorption properties of GDY, GDY/CdSe 2D/0D heterojunctions were successfully established and applied to photocatalytic hydrogen evolution. The hydrogen evolution activity of GDY/CdSe-20, a type of composite material, reached 6470 μmol g–1 h–1, which is 461 and 40 times higher than that of GDY and CdSe, respectively. Moreover, the fine electrical conductivity of GDY enabled rapid and effective transfer of the photogenerated electrons in CdSe into the hydrogen evolution reaction. The transfer path of the photogenerated electrons was studied through XPS with in situ irradiation, and a reasonable mechanism for the hydrogen evolution reaction was proposed. This study provides a feasible approach for the large-scale preparation of GDY and demonstrates the prospects of GDY in the field of photocatalysis.