As a new member of the carbon family, graphdiyne is an intrinsic semiconductor featuring a natural bandgap, which endues it potential for direct application in photoelectric devices. However, without cooperating with other active materials, conventional hexacetylene-benzene graphdiyne (HEB-GDY) shows poor performances in photocatalysis and photoelectric devices due to its non-ideal visible light absorption, low separation efficiency of the photogenerated carriers and insufficient sites for hydrogen production. Herein, we report a molecular engineering strategy for the regulation of GDY-based carbon materials, by incorporating a strong pyrene absorption group into the matrix of graphdiyne, to obtain pyrenyl graphdiyne (Pyr-GDY) nanofibers through a modified Glaser-Hay coupling reaction of 1,3,6,8-tetraethynylpyrene (TEP) monomers. For comparison, phenyl graphdiyne (Phe-GDY) nanosheets were also constructed using 1,3,4,6-tetraethynylbenzene (TEB) as a monomer. Compared with Phe-GDY, Pyr-GDY exhibits a wider visible light absorption band, promoted efficiency of the charge separation/transport and more sufficient active sites for water reduction. As a result, Pyr-GDY alone displays superior photoelectrocatalytic performance for water splitting, giving a cathode photocurrent density of ~138 μA cm⁻² at a potential of −0.1 Vversus normal hydrogen electrode (NHE) in neutral aqueous solution, which is almost ten and twelve times as high as those of Phe-GDY (14 μA cm⁻²) and HEB-GDY (12 μA cm⁻²), respectively. Such a performance is also superior to those of most reported carbon-based metal-free photocathode. The results of theoretical calculations reveal that the carbon atoms in the acetylene bonds are the active sites for proton reduction. This work offers a new strategy for the construction of graphdiyne-based metal-free photo-electrocatalysts with enhanced photoelectrocatalytic performance.

作为碳族的一个新成员，graphdiyne是一种具有天然带隙的本征半导体，这赋予了其在光电器件中直接应用的潜力。然而，由于不理想的可见光吸收，光生载流子的分离效率低以及制氢位点不足，传统的六乙炔-苯石墨二炔（HEB-GDY）在不与其他活性物质配合的情况下，在光催化和光电装置中表现出较差的性能。 。在这里，我们报告了一种分子工程策略，用于调节GDY基碳材料，方法是将强的absorption吸收基团掺入石墨二炔基体中，通过修饰的Glaser-Hay偶联反应获得pyr烯石墨二炔（Pyr-GDY）纳米纤维。 1,3,6,8-四乙炔基py（TEP）单体。为了比较，还使用1,3,4,6-四乙炔基苯（TEB）作为单体构造了苯基石墨二炔（Phe-GDY）纳米片。与Phe-GDY相比，Pyr-GDY表现出更宽的可见光吸收带，提高了电荷分离/传输的效率，并且具有更充分的水分还原活性位。结果，仅Pyr-GDY就表现出优异的水分解光电催化性能，阴极光电流密度约为138μAcm与中性水溶液中的普通氢电极（NHE）相比，在-0.1 V的电位下为^-2，几乎是Phe-GDY（14μAcm ^-2）和HEB-GDY（12μA）的十和十二倍cm ^-2）。这样的性能也优于大多数报道的碳基无金属光电阴极。理论计算的结果表明，乙炔键中的碳原子是质子还原的活性位点。这项工作为构建具有增强的光电催化性能的基于石墨二炔的无金属光电催化剂提供了新的策略。