Open AccessVisible-Light-Activated Type II Heterojunction in Cu3(hexahydroxytriphenylene)2/Fe2O3 Hybrids for Reversible NO2 Sensing: Critical Role of π–π* Transition
Author(s) -
YoungMoo Jo,
Ki-Taek Lim,
Ji Won Yoon,
Yong Kun Jo,
Young Kook Moon,
Ho Won Jang,
Jong Heun Lee
Publication year - 2021
Publication title -
acs central science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.893
H-Index - 76
eISSN - 2374-7951
pISSN - 2374-7943
DOI - 10.1021/acscentsci.1c00289
Subject(s) - heterojunction , selectivity , materials science , nanoparticle , visible spectrum , oxide , porosity , metal organic framework , nanotechnology , optoelectronics , metal , chemistry , catalysis , biochemistry , adsorption , metallurgy , composite material
Metal-organic frameworks (MOFs) with high surface area, tunable porosity, and diverse structures are promising platforms for chemiresistors; however, they often exhibit low sensitivity, poor selectivity, and irreversibility in gas sensing, hindering their practical applications. Herein, we report that hybrids of Cu 3 (HHTP) 2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) nanoflakes and Fe 2 O 3 nanoparticles exhibit highly sensitive, selective, and reversible detection of NO 2 at 20 °C. The key parameters to determine their response, selectivity, and recovery are discussed in terms of the size of the Cu 3 (HHTP) 2 nanoflakes, the interaction between the MOFs and NO 2 , and an increase in the concentration and lifetime of holes facilitated by visible-light photoactivation and charge-separating energy band alignment of the hybrids. These photoactivated MOF-oxide hybrids suggest a new strategy for designing high-performance MOF-based gas sensors.