Modulating the Conduction Band of MOFs by Introducing Tiny TiO2 Nanoparticles for Enhanced Photocatalytic Performance: Importance of the Loading Position

Xianqi Chen; Zihao Wei; Yaqiong Li; Qi Sun; Ning Ding; Lirong Zheng; Shuhu Liu; Wenxing Chen; Shenghua Li; Siping Pang

doi:10.1021/acs.inorgchem.3c00658

Modulating the Conduction Band of MOFs by Introducing Tiny TiO₂ Nanoparticles for Enhanced Photocatalytic Performance: Importance of the Loading Position

Inorg Chem. 2023 Jul 10;62(27):10572-10581. doi: 10.1021/acs.inorgchem.3c00658. Epub 2023 Jun 23.

Authors

Xianqi Chen¹, Zihao Wei¹, Yaqiong Li¹, Qi Sun¹, Ning Ding¹, Lirong Zheng², Shuhu Liu², Wenxing Chen³, Shenghua Li¹, Siping Pang¹

Affiliations

¹ School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China.
² Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China.
³ Energy & Catalysis Center, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.

PMID: 37350745
DOI: 10.1021/acs.inorgchem.3c00658

Abstract

The preparation of TiO₂ and metal-organic framework (MOF) into composite photocatalysts has been proven to be a mature and effective strategy to achieve stronger catalytic activity. In this work, we focus on exploring the significant effects and mechanisms of the relative positions of decorated titanium oxide nanoparticles and MOFs on the final catalytic activity. We first used a simple in situ method to encapsulate tiny TiO₂ nanoparticles into a Zr-MOF (PCN-222), where Zr-Ti bonds were created at the interface of the two components. Thanks to the strong interfacial interaction forces, band bending occurred in TiO₂@PCN-222 and a more negative conduction band (Δ = 0.26 V) with better electron transport properties was obtained. The results of photocatalytic CO₂ reduction experiments under visible light showed a 78% increase (142 μmol g^-1 h^-1) in the production rate of HCOO^-. Surprisingly, the loading of TiO₂ nanoparticles on the MOF surface (TiO₂@PCN-222) resulted in a significant decrease of 56% in the catalyst yield activity due to poor adsorption and electron transfer properties. This work demonstrates the possibility of tuning the band structure and catalytic activity of MOFs with the help of changing the position of the dopant and shows the importance of the rational design of MOF-based composites.