Controllable Synthesis of Two-Dimensional Graphdiyne Films Catalyzed by a Copper(II) Trichloro Complex

Abstract

Graphdiyne (GDY) is a carbon allotrope with an alkyne-rich framework constructed from the coupling of terminal alkynes in hexaethynylbenzene (HEB); thus, efficient acetylene–acetylene bond coupling is essential to synthesize high-quality GDY. In this work, a copper­(II) trichloro catalyst (CuTC) was introduced for GDY growth in the presence of a Cu foil, N,N,N,N′-tetramethylethylenediamine (TMEDA), and trichloromethane (CHCl3) at a mild temperature. High-quality GDY sheets on a gram scale can be obtained at a yield of 42% by increasing the content of HEB and Cu foil, which forms the foundation for their further applications. A mechanistic study demonstrated that Cu–Cl bonds play an important role in the formation of the Cu­(II)–diacetylide intermediate, which extended GDY growth to other benign solvents, such as dichloromethane (DCM), ethyl acetate (EA), tetrahydrofuran (THF), and N,N-dimethylformamide (DMF). Besides, GDY analogues H-GDY, COOCH3-GDY, and Py-GDY can be successfully grown on the surface of a Cu foil with a higher 1,3-diyne content than that mentioned in previous reports. GDY synthesized by the present method showed enhanced photocatalytic activity in hydrogen evolution upon hybridization with π-conjugated molecules through a π–π stacking interaction, which is powerful for constructing novel heterojunction materials by adjusting the electronic structure of GDY, thereby enhancing the light absorption ability of the system. Our work will contribute to the preparation of high-quality GDY and its analogues and extend their applications in various areas in the future.

CoV‐LDH‐Derived CoP2 Active Sites and ZnxCd1−xS Solid‐Solution Ingeniously Constructed S‐Scheme Heterojunction for Photocatalytic Hydrogen Evolution

“…Therefore, we measured UPS spectra and obtained the work functions of Zn x Cd 1− x S and P‐CoV‐LDH by formula Φ = hν − ( E Fermi − E Cutoff ), which are 3.19 and 4.9 eV, respectively. [ 61 ] According to this result, when Zn x Cd 1− x S and P‐CoV‐LDH contact each other, the photoexcited electrons of the composite catalyst should be transferred from Zn x Cd 1− x S to P‐CoV‐LDH to align the Fermi level. [ 62 ] This result corresponds to the fluorescence free radical capture experiment.…”

Fabrication of graphdiyne and its analogues for photocatalytic application

“…This work firmly confirmed the possibility of the interface-assisted approach to regulate the basic properties of GDY. What's more, the interface synthesis facilitates the preparation of GDY with specific functional groups, such as CN 36 and COOCH, 37 which extends GDY's applications in various areas in the future. Despite the outstanding merits of the interface synthesis, this method greatly suffers from the long-time reaction period and the uncontrollable side reactions.…”

A novel graphdiyne (CnH2n−2) synthesis strategy: design and application of an organic/inorganic conjugated system for photocatalytic hydrogen production

“…In addition, it is a promising material for photocatalytic hydrogen precipitation because of its large nanoscale pores, narrow band gap, and single-atomic level two-dimensional planar conjugation. 19 At present, it is difficult for a single material to give full play to its advantages in the field of photocatalytic hydrogen evolution. It is an effective means to give full play to the material properties by building composite materials to achieve the purpose of morphology control, band gap control and structure optimization.…”