Graphdiyne based GDY/CuI/NiO parallel double S-scheme heterojunction for efficient photocatalytic hydrogen evolution

Abstract

As a new kind of two-dimensional (2D) layered carbon allotrope, graphdiyne (GDY) is rarely studied in the application field of photocatalytic hydrogen production. In addition, the efficient construction of photocatalyst heterostructure is a promising strategy to improve the yield of hydrogen production from photocatalytic split of water. Therefore, it is an excellent method to construct heterostructure photocatalytic system by introducing GDY into semiconductor photocatalytic materials. Herein, it is an excellent method to construct heterostructure photocatalytic system by introducing the cuprous iodide based 2D layered carbon allotrope (GDY) into metallic oxide semiconductor (NiO). Thus, a ternary hybrid photocatalyst (GDY/CuI/NiO) was prepared by in situ ultrasonic agitation method. X-ray diffraction, SEM, transmission electron microscope and x-ray photoelectron spectroscopy results showed that NiO nanosheets were successfully adsorbed by GDY/CuI. In addition, the composite catalyst (GDY/CuI/NiO) showed excellent photocatalytic performance, which performed a high hydrogen production activity of 5955 μmol g−1 and good stability in the 20 h hydrogen production experiment. Amorphous GDY provides more active sites for the process of hydrogen evolution in this photocatalytic system. Most importantly, the construction of S-scheme heterojunction promotes electron transfer and plays an important role in enhancing the hydrogen production activity. These findings provide new ideas for realizing efficient solar hydrogen production system.