Herein, covalent triazine frameworks in eclipsed AA and staggered AB stacking modes are respectively used for the in-situ growth of TiO₂, and two heterostructures are obtained. Due to the highly organized stacking of the molecular layer in CTF-AA that strengthens the interlayer interaction, the light absorption and carrier migration of CTF-AA/TiO₂ are both enhanced in comparison to those of its component or CTF-AB/TiO₂. Correspondently, the photocatalytic CO₂ reduction reaction (CO₂RR) of CTF-AA/TiO₂ proffers 9.19 μmol·g^–1·h^–1 CH₄ and 2.32 μmol·g^–1·h^–1 CO production, about 9.2 and 4.3 times greater than that of pristine TiO₂, respectively. Even though the innate photoresponse of the triazine unit endows CTF-AB/TiO₂ with augmented light capturing, its photocatalytic CO₂ conversion is relatively insignificant. According to the analyses of the planar-averaged electron density difference and Bader charge, the unproductive CO₂ efficiency might be due to the insufficient interfacial electron transfer from TiO₂ to CTF-AB. Given that the ΔG (−3.22 eV) of CHO intermediate generation is lower than that of CO desorption (−1.23 eV), the reaction tends to further generate CH₄ other than yielding CO. This study could shed fresh light over the reasonable design of effective photocatalytic heterostructures.

中文翻译：

---

调控 CTF-TiO2 异质结构的层堆叠构型以提高光催化 CO2 还原


在此，分别使用日蚀 AA 和交错 AB 堆叠模式的共价三嗪框架用于 TiO₂ 的原位生长，并获得了两种异质结构。由于 CTF-AA 中分子层的高度组织化堆叠加强了层间相互作用，因此与其组分或 CTF-AB/TiO₂ 相比，CTF-AA/TiO₂ 的光吸收和载流子迁移均得到增强。相应地，CTF-AA/TiO₂ 的光催化 CO₂ 还原反应 （CO₂RR） 产生 9.19 μmol·g^–1·h^–1 CH₄ 和 2.32 μmol·g^–1·h^–1 CO，分别是原始 TiO₂ 的 9.2 倍和 4.3 倍。尽管三嗪单元的先天光响应赋予 CTF-AB/TiO₂ 增强的光捕获能力，但其光催化 CO₂ 转化相对微不足道。根据平面平均电子密度差和 Bader 电荷的分析，低效的 CO₂ 效率可能是由于从 TiO₂ 到 CTF-AB 的界面电子转移不足。鉴于 CHO 中间体生成的 Δ G （-3.22 eV） 低于 CO 解吸的 ΔG （-1.23 eV），该反应倾向于进一步生成 CH₄，而不是产生 CO。本研究可为合理设计有效的光催化异质结构提供新的思路。