Graphdiyne (GDY) alone as a photocatalyst is unsatisfactory because of its low crystallinity, limited regulation of the band gap, weak photogenerated charge separation, etc., and heterojunctioning with other materials is necessary to activate the photocatalytic activity of GDY. Through elaborate design, a diacetylene-rich linker (S2) was prepared and employed to construct a crystalline and structurally well-defined GDY-like covalent organic framework (COF, namely S2-TP COF) which merges the merits of both COF and GDY to boost the photocatalytic hydrogen evolution reaction (HER). By theoretical prediction on the donor–acceptor (D–A) pair, two other monoacetylene-bridged COFs (S1-TP COF and S3-TP COF) were prepared for comparison. Exhibiting enhanced separation and suppressed recombination of photogenerated excitons, Pt-photodeposited S2-TP COF showed a higher HER rate (10.16 mmol g−1 h−1) than the other two non-GDY-like COFs (3.71 and 1.13 mmol g−1 h−1). A joint experimental–theoretical study suggests that the appropriate D–A structure for photogenerated charge separation and diacetylene motif as the adsorption site are the key reasons for the boosted HER. This work opens a new avenue for the rational design of COFs as GDY mimics for photocatalytic application.
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机译：石墨炔 （GDY） 单独作为光催化剂并不令人满意，因为它的结晶度低、带隙调节有限、光生电荷分离弱等，与其他材料的异质结是激活 GDY 光催化活性所必需的。通过精心设计，制备了富含二乙炔的接头 （S2） 并用于构建结晶且结构明确的 GDY 样共价有机框架 （COF，即 S2-TP COF），该框架融合了 COF 和 GDY 的优点，以促进光催化析氢反应 （HER）。通过对供体-受体 （D-A） 对的理论预测，制备了另外两个单乙炔桥 COFs （S1-TP COF 和 S3-TP COF） 用于比较。Pt 光沉积的 S2-TP COF 表现出增强的分离和抑制光生激子的复合，显示出比其他两种非 GDY 样 COFs（3.71 和 1.13 mmol g-1 h-1）更高的 HER 速率 （10.16 mmol g-1 h-1）。一项联合实验-理论研究表明，用于光生电荷分离的适当 D-A 结构和作为吸附位点的二乙炔基序是增强 HER 的关键原因。这项工作为理性设计 COF 作为光催化应用的 GDY 模拟物开辟了一条新途径。
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