In Situ X-ray Photoelectron Spectroscopy (XPS) Demonstrated Graphdiyne (g-CnH2n–2) Based GDY-CuI/NiV-LDH Double S-Scheme Heterojunction for Efficient Photocatalytic Hydrogen Evolution

Abstract

As a new two-dimensional layered carbon material, graphdiyne (GDY) is widely used in various fields because of its excellent electrical conductivity and tunable electronic structure. In this work, graphdiyne, a two-dimensional layered carbon material, is prepared by an alkyl terminal coupling method using Cu+ as a catalyst. Nickel–vanadium hydro calcite (NiV-LDH) is anchored on the surface of GDY-CuI bya solvothermal method to form a double S-scheme heterojunction photocatalytic hydrogen precipitation system. The double S-scheme heterojunction suppressed the electron–hole recombination in the composite catalyst, which greatly improved the transfer rate of photogenerated carriers. Meanwhile, a tight and unique interface is formed in the composite, which not only accelerates the separation and transfer of electron holes but also improves the catalytic stability of the composite. H2 (73.65 μmol) is produced in 5 h in triethanolamine solution, which is 4.1 and 3.7 times higher than those with NiV-LDH and NiV-LDH/CuI. Twenty-five hour cycling experiments demonstrated the catalytic stability of the materials. This work provides an effective strategy for the rational construction and application of graphdiyne group hetero structures in the field of photocatalytic hydrogen evolution.