Superior NO2 Sensing of MOF-Derived Indium-Doped ZnO Porous Hollow Cages

Highly sensitive semiconductor gas sensors hold great potential for applications in trace detection. Reliable detection of ppb-level NO2 is crucial environmental monitoring, which however still remains a challenge. In this work, we adopted one-pot encapsulation strategy synthesizing indium-doped ZnO porous hollow cages. In(acac)3 was selected as the indium source due to its molecular diameter between cavity size (11.6 Å) and aperture (3.4 ZIF-8. During crystallization progress ZIF-8, it situ trapped cavities In(acac)3@ZIF-8 composites were formed (Scheme a, b). calcination, metal ion species, composed In(acac)3@ZIF-8, oxidized, leading formation In-doped cages c, d). case, ZIF-8 served host backbone uniform distribution well production structure. doping led significantly enhanced NO2-sensing performance, achieving response 3.7 10 ppb NO2, high sensitivity 187.9 ppm-1, limit low 0.2 ppb. The mechanism properties discussed terms intrinsic excellent accessibility structure electronic sensitization by doping. Our findings could be extended design other doped oxides performance applications.