School of Chemistry and Materials Science, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China (USTC), Hefei, 230026, China.
Phys Chem Chem Phys. 2019 Jan 2;21(2):546-553. doi: 10.1039/c8cp04373f.
A newly reported woven covalent organic framework (COF-505) with a stable and flexible structure is believed to be a promising candidate for photocatalysis. Here, we carried out density functional theory calculations to investigate the properties of COF-505 related to photocatalysis. We first investigated the ability of visible light absorption by this COF-505. Variations of central metal ions and the dihedral angle between two adjacent ligand groups were respectively taken into account for adjusting its light harvesting capabilities. Replacing the original Cu(i) ions with Pd(ii) ions causes a red shift in the visible light region. Increasing the dihedral angle results in an increase of the band gap for COF-505 with Cu(i) and a decrease for COF-505 with Pd(ii), respectively. The potential of COF-505 as a photocatalyst was furthermore explored by studying the adsorption of H2, CO2 and H2O on it. All molecules can be stably adsorbed. In particular, COF-505 with Pd(ii) exhibits appreciable O-H activation of the adsorbed H2O in the presence of a positive charge, which is promising for initiating water splitting. Overall, our results suggest that COF-505 holds great potential for photocatalytic applications.
一种新报道的具有稳定和灵活结构的编织共价有机骨架（COF-505）被认为是一种有前途的光催化候选材料。在这里，我们进行了密度泛函理论计算，以研究与光催化相关的 COF-505 的性质。我们首先研究了这种 COF-505 吸收可见光的能力。分别考虑了中心金属离子的变化和两个相邻配体基团之间的二面角，以调整其光捕获能力。用 Pd(ii)离子取代原始的 Cu(i)离子会导致可见光区域的红移。增加二面角会导致 COF-505 与 Cu(i)的能带隙增加，而 COF-505 与 Pd(ii)的能带隙减小。通过研究 H2、CO2 和 H2O 在其上的吸附，进一步探讨了 COF-505 作为光催化剂的潜力。所有分子都可以稳定吸附。特别是，在带正电荷的情况下，具有 Pd(ii)的 COF-505 对吸附的 H2O 表现出可观的 O-H 活化，这对于引发水分解很有前景。总的来说，我们的结果表明 COF-505 在光催化应用方面具有很大的潜力。
