Regulating the Layer Stacking Configuration of CTF-TiO<sub>2</sub> Heterostructure for Improving the Photocatalytic CO<sub>2</sub> Reduction
Liqiang Jing, Yu Xia, Zhiting Zhang, Xiaolong Zhao, Lei Wang, Jingwei Huang, Houde She, Xinheng Li, Qizhao Wang
Abstract
Herein, covalent triazine frameworks in eclipsed AA and staggered AB stacking modes are respectively used for the in-situ growth of TiO 2, 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/TiO 2 are both enhanced in comparison to those of its component or CTF-AB/TiO 2 . Correspondently, the photocatalytic CO 2 reduction reaction (CO 2 RR) of CTF-AA/TiO 2 proffers 9.19 μmol·g –1 ·h –1 CH 4 and 2.32 μmol·g –1 ·h –1 CO production, about 9.2 and 4.3 times greater than that of pristine TiO 2, respectively. Even though the innate photoresponse of the triazine unit endows CTF-AB/TiO 2 with augmented light capturing, its photocatalytic CO 2 conversion is relatively insignificant. According to the analyses of the planar-averaged electron density difference and Bader charge, the unproductive CO 2 efficiency might be due to the insufficient interfacial electron transfer from TiO 2 to CTF-AB. Given that the Δ G (−3.22 eV) of CHO intermediate generation is lower than that of CO desorption (−1.23 eV), the reaction tends to further generate CH 4 other than yielding CO. This study could shed fresh light over the reasonable design of effective photocatalytic heterostructures.