Photocatalytic overall water vapor splitting (OWVS) into H2 and O2 not only owns the potential of avoiding the backward reaction of O2 reduction reaction reforming H2O, but also realize H2 production without available liquid water. However, this attempt is still a blank due to the weak absorption of photocatalysts to water vapor. Herein, we report the first example of visible‐light‐driven OWVS by combining the water‐adsorbing ability and photocatalytic activity of covalent organic frameworks (COFs). The overall water splitting activity of Tp‐COF skeleton was realized by introducing tripyridyltriazine segment. The Pt@Tp‐TAPyT‐COF achieves high visible‐light‐driven H2 and O2 evolution rates of 148.4 and 74.8 μmol g‐1 h‐1, respectively. Under water vapor conditions, the Pt@Tp‐TAPyT‐COF could drive OWVS even without backward reaction. By further optimizing the structure of β‐ketoamine section, it was found that the Pt@DHTA‐TAPyT‐COF showed optimal OWVS activity, with the H2 and O2 evolution rate of 51.2 and 25.6 μmol g‐1 h‐1 respectively. The advantage of OWVS compared to traditional solid‐liquid OWS was further confirmed by a continuous activity test of 45 h. Further experiments indicated that carbonyl‐O and pyridine‐N atoms in COFs server as water absorbing sites, and the absorbed water molecules could promote water splitting in COFs simultaneously.

中文翻译：

---

用于光催化整体水蒸气分解的工程共价有机框架


光催化整体水蒸气分解 （OWVS） 转化为 H2 和 O2 不仅具有避免 O2 还原反应重整 H2O 的逆向反应的潜力，而且可以在没有可用液态水的情况下实现 H2 的生产。然而，由于光催化剂对水蒸气的吸收较弱，这种尝试仍然是空白的。在此，我们通过结合共价有机框架 （COF） 的水吸附能力和光催化活性，报告了可见光驱动的 OWVS 的第一个例子。通过引入三吡啶三嗪链段实现 Tp-COF 骨架的整体分解水活性。Pt@Tp-TAPyT-COF 实现了可见光驱动的 H2 和 O2 释放率，分别为 148.4 和 74.8 μmol g-1 h-1。在水蒸气条件下，即使没有反向反应，Pt@Tp-TAPyT-COF 也可以驱动 OWVS。通过进一步优化β-酮胺切片的结构，发现Pt@DHTA-TAPyT-COF表现出最佳的OWVS活性，H2和O2的释放速率分别为51.2和25.6 μmol g-1 h-1。45 h 的连续活性测试进一步证实了 OWVS 与传统固液 OWS 相比的优势。进一步的实验表明，COFs 中的羰基 O 原子和吡啶原子是吸水位点，吸收的水分子可以同时促进 COF 中的水分解。