Preparation of N‑Graphdiyne Nanosheets at Liquid/Liquid Interface for Photocatalytic NADH Regeneration

Two-dimensional (2D) N-graphdiyne (N-GDY) nanosheets containing different number of N were synthesized by polymerization of triazine, pyrazine, and pyridine-based monomers at liquid/liquid interface. The configurations and nanostructures of N-GDY were well-characterized. The wettability changed to more hydrophilic as the N contents increased. The collected N-GDY was further employed as metal-free photocatalyst for NADH regeneration. The catalytic performance was related with the N content in the graphdiyne. The N3-GDY demonstrated the best activity. This strategy provided a new promising platform of designing unique 2D N-GDY with tunable performance in biorelated catalysis

Interfacial Synthesis of Conjugated Two-Dimensional N‑Graphdiyne

We explored the interfacial synthesis of 2D N-graphdiyne films at the gas/liquid and liquid/liquid interfaces. Triazine- or pyrazine-based monomers containing ethynyl group were polymerized through the Glaser coupling reactions at interfaces. Several layered, highly ordered and conjugated 2D N-graphdiyne were obtained. Their structures were characterized by TEM, SEM, AFM, XPS, and Raman spectra. Thin films with minimum thickness of 4 nm could be prepared

Highly Conjugated Three-Dimensional Covalent Organic Frameworks Based on Spirobifluorene for Perovskite Solar Cell Enhancement

Highly conjugated three-dimensional covalent organic frameworks (3D COFs) were constructed based on spirobifluorene cores linked via imine bonds (<b>SP-3D-COFs</b>) with novel interlacing conjugation systems. The crystalline structures were confirmed by powder X-ray diffraction and detailed structural simulation. A 6- or 7-fold interpenetration was formed depending on the structure of the linking units. The obtained <b>SP-3D-COFs</b> showed permanent porosity and high thermal stability. In application for solar cells, simple bulk doping of <b>SP-3D-COFs</b> to the perovskite solar cells (PSCs) substantially improved the average power conversion efficiency by 15.9% for <b>SP-3D-COF 1</b> and 18.0% for <b>SP-3D-COF 2</b> as compared to the reference undoped PSC, while offering excellent leakage prevention in the meantime. By aid of both experimental and computational studies, a possible photoresponsive perovskite–<b>SP-3D-COFs</b> interaction mechanism was proposed to explain the improvement of PSC performance after <b>SP-3D-COFs</b> doping