Strategic energy-level modulation in porous heterojunctions: advancing gas sensing through Type-I to Type-II transitions
Xiaopeng Cheng, Yiming Xu, Xiao‐Liang Ye, Zhi-Peng Luo, Shipeng Zhu, Kefeng Li, Jiangfeng Lu, Guan‐E Wang, Gang Xu
Abstract
To significantly enhance reaction efficiency of porous heterojunctions in various applications, precise engineering of customization heterostructures through energy-level modulation is indispensable. Herein, the preparation of a core-shell porous heterojunction, UiO-66@TDCOF, is reported. Taking advantage of adjustable structure of metal-organic frameworks (MOFs), the energy-level of UiO-66 core is tailored to precisely align with that of porphyrin-based covalent organic framework (denoted as TDCOF) shell. As a results, the heterojunction transitions flexibly from a type-I to a type-II configuration, which remarkably enhances the efficiency of charge separation under light irradiation, resulting in exceptional performances in chemiresistive gas sensing. Notably, the sensitivity of (NH2)1.24-UiO-66@TDCOF towards NO2 is at a high level among all reported heterojunctions under visible-light condition, surpassing the majority of previously reported MOF and COF materials. This research not only presents a strategy for the design of heterojunctions but also gives an approach to material design tailored for chemical applications. A porous heterojunction is customized to transform from type-I to type-II through precisely regulating the energy level, which remarkably enhances the reaction efficiency, resulting in exceptional performance in chemiresistive gas sensing.